I'm using Adobe Photoshop CS3 for this. But I think that aside from the coloring I used, it should be translatable since I mostly used layer blending modes (I'm not sure)
Things covered: Layer blending modes, Curves adjustment layers, High Pass filter sharpening (I'm not covering the coloring)
Since this tutorial was aimed at people who don't know much about Photoshop or are still learning, I'll try to explain the thought process behind each action and what some tools do, so excuse me if this gets too wordy (warning: it IS very wordy). So you could use some of the things I'm teaching here in other kinds of graphics too, not just wallpapers.
But even then, in order to spare people from reading such a wall of text in case they already know how things work, I'm providing some tl;dr's in the form of bolded text.
1. Create a new file. The size I chose for this wallpaper is 1920x1080, so I set the canvas to the appropriate size. The screenshots I'll be using to illustrate the steps will be resized down to 1366x768 though, to make it easier on loading times.
2. Let's start making the background now. First, I pasted the background of the Sheol Gate (which I got here, in the "Continuum Shift Story Mode Backgrounds!" link) since it's Nu's stage, and resized it so it covers the whole canvas. (Ctrl+T, hold Shift while dragging the little boxes at the corner, for those who don't know)
I also positioned it in a way that the Cauldron (the gold hole) is in the general position I'll place Nu at later on, as it would help with making her the focus of the wallpaper (despite the fact the background will end up barely visible).
After resizing and positioning the Sheol Gate story mode background
3. Just the Sheol Gate background looks a bit too plain, though. I'm going to add something else, but first let's make it black and white to not have it turn into a mess of colors later on.
First, desaturate the background (Ctrl+Shift+U) to make it black and white. It's boring now, so let's add some more contrast to make it look better.
To do this, I duplicated the B&W layer and set the Blending Mode to Screen. Then I duplicated it again and set it to Soft Light. (Just to clarify, the order the layers should be is Base > Screen > Soft Light, from bottom-top)
The Screen layer lights up the picture, while the Soft Light one gives it more contrast. In this case I'll just leave both layers at 100% opacity, but often you'll need to adjust each layers' opacities to avoid overly bright or contrasted images.
After desaturating and setting the duplicate layers to Screen and Soft Light blending modes
4. Now that we're done adjusting the Sheol Gate background, let's add the something else I was talking about before. I'm getting another background from the same link I posted at step 2, the "Unknown" one. Paste it on the canvas.
As for resizing/positioning it, I found that I didn't need to resize it. I just positioned it in a way that the center of the swirly thing is right on top of the Cauldron in the Sheol Gate background. (This would be to aid with the focus thing I mentioned before)
Anyway, after pasting and positioning it, I set its Blending Mode to Multiply to mix the the details of the Sheol Gate background with the Unknown background. The reason I picked Multiply is that the Unknown background is somewhat dark, so it would make the dark parts blend nicely with the background underneath it. I can't say the same about the light swirly parts though, since they're light colors and Multiply makes light colors more transparent...
"Unknown" background on Multiply blending mode
5. Ick, what the heck am I doing? That looks terrible, doesn't it? Way too dark and the light blue swirls look bad. Let's fix that.
Duplicate the Unknown background layer and change its Blending Mode to Screen. Well, now the supposedly dark parts are too bright and most of the detail we got from the other background was lost. To fix this, we're going to adjust the Brightness/Contrast of this layer. (Image > Adjustments > Brightness/Contrast)
Remember how I said Multiply makes light colors transparent? Screen is the exact opposite of it, making dark colors transparent. So we want to make the dark parts really dark so they don't get brightened up, while keeping the light swirls mostly intact to keep them defined (the Multiply layer destroyed the light swirls)
Enough rambling, here's the settings I used: -70 Brightness and +50 Contrast ("Use Legacy" box ticked). It's a bit extreme, I know, but the contrast makes the dark parts much more darker while keeping the swirls mostly bright, and the brightness keeps the swirls from getting blindingly bright, as well as aiding with keeping the dark parts dark.
The Screen layer after adjusting the Brightness/Contrast
Now that we adjusted the Screen layer properly, it looks much better... However, it's still a little too bright and I want to keep the Sheol Gate details more visible, so I lowered the opacity of this layer to 30%.
The same layer after adjusting the opacity
You may be asking, what was the point of that? It was to define the light swirls better.
6. Done with the background business. Now it's time to add Nu to it.
First of all, I'm going to add the main render to make it easier to build the wallpaper around it. (I recolored that artwork using the Lambda template from here)
Remember how I said earlier that I was placing the Cauldron (and consequently the center of the swirls) where I was going to place Nu? Well, that means I'll placing that render right on top of the center of the swirls.
After pasting and positioning the render
7. But that's not all. Let's spice up her colors by making them more vivid. Start off by duplicating the artwork layer and setting it to Multiply blending mode.
"The heck is she doing?", you ask. That's to bring out the colors more. It's pretty dark now, yes, but we're about to fix that by duplicating the layer again and setting it to Screen to lighten it up. Remember to adjust the opacity to not make it way too bright (I set the opacity to 70%).
To finish it off and add that extra contrast, duplicate the layer once again and set it to Soft Light. Remember to adjust the opacity to not make it overly contrasted (I set it to 75%)
...I guess I was lying when I said "to finish it off". There's one more thing, and that's sharpening. I dislike blurry focuses, as slight as it may be, thus! Duplicate the layer again and set it to Overlay blending mode. Now go to Filter > Other > High Pass and adjust it as needed (remember that the value doesn't need to be high, most likely anywhere around or under 1 will do the job). Try to not oversharpen it or it'll look ugly. For a better explanation of using the High Pass filter for sharpening, see this other tutorial.
To clarify: The order of the layers should be like this: Base > Multiply > Screen > Soft Light > Overlay/High Pass (from bottom-top)
Lastly, I'm going to add some Drop Shadow (Layer Styles, it's one of the icons at the bottom of the layers palette) to the base layer to add some depth (yeah, that's a lame way of doing that, I know). 14 Distance and Size looked good for me.
Oh yes, in order to make sifting through layers easier, I recommend grouping all the layers related to the main render together (Ctrl+G, drag the layers into the group) and then collapsing the group.
The render after the blending mode layers treatment and adding the drop shadow
8. Now that we're done with tweaking the main render, let's move onto other background details. I'm going to add Nu's emblem behind her (in a layer under her render, of course). Since the background is dark, I'm going to invert the colors of the emblem (Ctrl+I) to make it visible. Then resize and position it behind her nicely.
The emblem placed behind her after resizing
You're wrong if you think I'm done with it. We need to blend it in a little better, you know?
9. First, let's color it a light blue (Edit > Fill) since the color theme of this wallpaper is blue, then change its blending mode to Linear Dodge. This is to make it look elegantly transparent (lol) and shiny (Linear Dodge works well with light colors). If you didn't choose a good shade of blue right off the bat, just mess around with the color with Hue/Saturation and Brightness/Contrast until you get something that looks good (which is even easier to preview now that the blending mode is at the right setting)
To add to the glowy/shiny feel, I'm going to add Outer Glow (Layer Styles) - a blue glow at Screen blending mode, 60% opacity and 7px size.
The emblem after blending it in
10. Now for the other background detail - the faded armorless Nu. I pasted this Nu artwork on a layer under the emblem, resized and positioned it in a way that clearly shows her face and shows as much detail of her sword and poncho thingy as possible.
The artwork after positioning it
11. Now, I'm going to set its Blending Mode to Hard Light to, well, blend it in. But it looks too bright, so I decided to lower the opacity to 60%. Now it looks way too faded, so I duplicated the layer and left it at Hard Light but with 50% opacity - This is to make the artwork more defined once again.
After blending it in
You must be thinking that was pretty pointless. Well, in reality I only duplicated the layer to keep the face defined. The rest should be more faded to keep her better blended in.
12. Thus I'll add a Layer Mask (here's a tutorial on how layer masks work) to the top most Hard Light layer and brush some black on the mask with a large (around 600px), soft round brush. I set the brush's Flow to 20% so I could brush some parts more than others. I brushed around the edges of the artwork while keeping her head intact.
A quick shot of how my layer mask looked like and how the artwork looked like with the layer mask
13. To finish it off, I'm going to blur it a little to help keep the focus on her armored artwork. Blur (Filter > Blur > Gaussian Blur) both Hard Light layers by the same amount. I can't remember how much I blurred it, but it was just enough to keep the focus on the other artwork while still keeping this one somewhat defined.
After blurring the artwork on the background
Phew... I'm done with laying the base pieces down. Now onto better blending everything together...
14. Next, I'm going to add this texture (which I got from here) on top of everything on Lighten Blending Mode at 65% opacity, without forgetting to stretch it so it covers the whole canvas. This is to add some misty lights and to help blend everything together, but also because I think it makes it look pretty. Also, the texture is already perfectly positioned without me needing to flip it around because the most clouded part is over the background-Nu, which helps give her that faded feel even more.
After adding the texture and adjusting it
15. The details on it look too defined for my taste... So I'm going to blur the texture a lot to make those hard white lines look more like mist.
Lastly, I erased some parts of the texture that were over things like Nu's face, her retracted leg and her arm because they were too clouded and to also add some depth (as if they were popping out of the mist). Of course, I used a large soft brush again with low flow.
After blurring and slightly erasing the unwanted parts
16. Moving on... I'm going to add some more mist to the bottom of the wallpaper to help keep the focus on the top half, and to also help the bottom of background-Nu blend in better. Using this texture (I don't know who made it, I randomly found it), I pasted it twice, changed both layers' blending modes to Lighten to give them that steamy look, and then changed the Hue/Saturation (Image > Adjustments > Hue/Saturation) to make them mostly blue. Then it was just a matter of positioning them where I wanted (at the bottom of the wallpaper, one on each side)
After adjusting and positioning the textures
Well, that looks pretty crappy and very not mist-like, so let's lower their opacity. 20% for the right texture and 30% for the left texture. Oh yeah, I forgot to mention that I positioned them this way to also make it look like Nu's leg is above the mist.
After lowering the textures' opacities
17. Added this texture (which I got from here) on top of everything, stretched it so it covers the whole canvas and set its Blending Mode to Soft Light. This is mainly to darken the edges to help even more with the focus (notice how the dark parts of the texture darken the image while the bright parts lighten it up on Soft Light). I had to make sure the bright parts were over Nu's face if possible, so I flipped the texture horizontally and vertically (Edit > Transform > Flip Horizontally/Vertically) as well.
And to make sure it didn't add any weird colors to the color scheme, I used Hue/Saturation once again to change its color to mainly blue.
After applying the texture on Soft Light
18. This next part is a bit tricky to explain since I had to change the original texture quite a bit to make it fit, so hopefully I can explain it clearly.
I added this texture (which I got from here) and set it to Screen. I used Hue/Saturation to change it's color to blue (although some other color would probably have worked as well since it's a light effect coming out of her claw).
However, as you might've noticed, it's horribly bright... Remember how I used Brightness/Contrast to fix the Screen layer back at step 5? I'm going to do that to this texture, too. I adjusted the Brightness and Contrast enough to make the background of that texture completely black while still keeping the light line bright enough (I'm sorry, I don't remember the exact settings I used for this... But it follows the same concept as the other step)
Once that was done, I resized, flipped and positioned this texture in a way that makes it look like it's coming out of Nu's claw. Also, I blurred it a little because I thought the lines were too hard.
After adjusting the texture
19. But there's some blue stuff on Nu's face and the light of the texture ends rather abruptly, as if it was cut-off... To fix that, I'm going to use a Layer Mask on this layer. I also took this opportunity to erase some other ends of the light lines so they look like they're fading away.
A shot of how my layer mask looked like
After that was done, I brushed some white on top of the light texture in another layer with a large, soft round brush. Then set its Blending Mode to Soft Light at 65% opacity. This is just to add some extra subtle glow to the light line.
After erasing some parts of the light texture and adding the faint glow
20. Enough of textures, let's add some extra decorations now... I used these tech brushes to add some tech shapes since Nu is a cyborg and all. I stamped them around in a white color, each in a separate layer. To make them look glowier, I changed all of their blending modes to Overlay and lowered their opacities (this varied between each layer)
When scattering the brushes around, I avoided placing them over Nu's face - the places where the focuses are. For the brush I placed around armored-Nu, I had to erase the parts over her.
After distributing the brushes throughout the wallpaper
21. Everything is nice and all, but the wallpaper looks too cloudy / full of fluff now... To fix this, I'm going to add a Curves adjustment layer (Layer > Adjustment Layers > Curves)
Let me try to explain how this works and what I'm trying to do. I want to increase the contrast of the wallpaper to decrease the amound of fluff without making it blindingly bright or really dark. So in other words, I want to make the dark parts of the wallpaper darker while keeping the bright parts mostly untouched.
Now, briefly explaining basic of the curves adjustment I'm going to use: (Skip this if you already know how curves adjustment layers work)
In the curves adjustment window, there's a grid. The bottom-left part of the grid changes the shadows (dark colors) of the picture, while the top-right part changes the highlights (light colors) and the middle changes the midtones. By clicking and dragging in this grid, you'll be placing a small point on it which you can later drag around to adjust the line that will appear in the grid.
This line is what indicates how the colors of the picture are getting affected. If you pull the bottom part of it towards the bottom-right side, you'll be making the shadows darker; If you pull it towards the top-left side, you'll be making the shadows brighter. if the line stays in the center, the colors will be left mostly untouched.
Hopefully that makes sense.
Here's a picture to help illustrate that, as well as showing the settings I used:
And here's how my picture looks now:
Wallpaper after adjusting curves
22. Now comes the coloring... I could easily keep it with natural coloring, but I want to blend everything together even more by unifying the colors. The problem is that I used a bunch of adjustment layers for this, which would make this tutorial EVEN longer than it already it... And I don't think this coloring would work on other pictures, so I'm going to skip writing about the coloring. If people -really- want me to, though, I'll write about it.
After applying all the coloring junk... which maybe I'll explain later
23. For the last part, I'm going to add the decorative text. I want to emulate the font BlazBlue uses for characters' names in the VS screen. To achieve that, I typed in all caps using the Times New Roman font on bold with a white color, then rasterized the layers (right-click on text layer > Rasterize Type) to be able to edit them. Then I edited the letters needed (in the case of "ν-13-", I didn't need to, but in "Awakening the Chaos" I had to edit the A's and O) and added an Outer Glow around the text.
After that, I positioned the text like I wanted by breaking it in multiple lines (in this case, I think putting all the text in a single line would look bad).
For additional decoration, I typed "Sword Summoner" in black and "Jellyka, Saint-Andrew's Queen" font, and placed it beneath the main text (the white glowy ones) on Soft Light to make it subtler.
Then I picked a Nu sprite (which I obtained here), filled it with light gray (so it looks like just a sillouette) and set it to Overlay to make it nicely transparent and shiny. Then I added a black Outer Glow to it on Overlay to keep it from blending into the background way too much and placed it next to the text after resizing it.
I moved all the text to next to background-Nu and noticed that the white text was hard to read because the background it's on is bright... To solve that, I brushed some black underneath all text layers and set it to Soft Light, 75% opacity. This is to darken the background a bit to help make the text readable.
After adding all the text stuff
24. For the finale, sharpen the whole wallpaper with High Pass by making a new layer, applying the image on it (Image > Apply Image) and then using the High Pass filter like in the end of step 7.
...And that's all! I hope that you find this useful. Any questions, just ask.