Very friendly and pleasant shapes and some well measured use of space in the disposition of the characters and their size and position between each other (I'd personally enjoy more room for the background but I believe that's a stylistic choice). An engaging use of color in the contrast between the lighter tones on the left side (with blue being notable) and the darker ones on the right behind Ryuko (with red calling attention); I'd perhaps consider placing Mako and the family on the left if a heroes x villains duality was a part of your vision but naturally that would mean a whole set of implications for the whole picture, so I don't know. Anyway, also perhaps due to the aesthetics of the source material but I appreciate the simplicity on the texturization or even barely any at all depending on where you look, I think it emanates some calmness which fit nicely with the shapes (funny that I usually suggest more texturization on reviews, today's an exception). What would take for me to give it a 5/5 would be some very detailed and expressive linework, something deeply tied to your personality, because you have the skills but I humbly believe something like that is the only thing missing. That's it.