First design is similar to your layout, since the background is crowded we need big and bold letters so they don't get lost. Because the title is a single line, a tall font works better here. There's a custom shadow behind every text so it pops against the background (except for the spine text where it's not needed).
Legibility is high with this design and the cover art isn't compromised with huge texts. The larger titles also have a transparent gradient to break the monotony. We could also make certain letters on the title more scifi-ish to add some flavour, like remove the bridges from the A's etc.
This one is more decorative and screams fantasy. It's not as modern or legible as the previous design but it draws more attention and looks good in thumbnail size. It also complements the artwork. The biggest downside is that the title text covers the crystal flame of the cover art.
Another modern design, this one uses a single font and is very symmetrical. The back cover text also has some of the words enlarged to draw attention to some of the keywords. We could apply this to any one of the designs if it's to your liking and change the bigger words to any of your choice. As with the first design it's also possible to get rid of the bridges on the A's or the spines of the E's for a more futuristic look.
The back page of this one is the same as "Design 2". The title font is unique and fits the layout well, it has an almost runic feeling to it and it's not as strong in fantasy theme as the second design but it still has a mystical feeling. Also complements the art style.
Has a tall and futuristic title. The biggest advantage of this one is it doesn't block the art at all but is still legible from a distance. All of the text has some glow to it, including the text of the back cover. The back cover also doesn't have as strong a shadow as the previous designs.