Hey Tensu, just dropping by to say that I love the coloring in your banners!
The muted tones in the Edward banner look great and I like how the colorful, bright effects stand out over everything else in [
this banner].
If anything, you seem to only have an "empty space" problem with graphics (I've noticed that you keep a lot of negative space), but there are a few piece where there's a lot going on, so it could be a matter of personal preference.
Either way, you should keep practicing! I get the impression that you're slowly but steadily getting to a good point with both your art and graphics, and I'm eager to witness how you'll improve in the future :-]