I didn't play Fire Emblem Engage, but I did watch a Let's play of the game. I was looking forward to seeing Alear's dragon form, but the game never showed it (no, Tiki's power don't count). So I decided to draw it myself, based on Alear's fell dragon heritage, but with more divine aspects to it. Hence why it looks like a snake and not a cobra. Also, these colors are when Alear becomes an emblem.

Fire Emblem (c) Nintendo