Okay, now I have a few ideas for Izuku's Dragon name.
"Green-Winged hero": Green-Winged-Hero. Graagviingaalhun.
"Wings that Vanquish Evil": Wings-Vanquish-Evil. Viingqahnaarvokun. (I personally like this one. Despite being over the 3-4 syllables Dragon names usually are, but this is a new version of the Dovah.
"Strong-Voiced Hero": Strong-Voice-Hero. Mulzulhun.
"Hero that Silences Evil": Hero-Silence-Evil. Hunnaholkvokun.
"Evil-Hunter on the wing": Evil-hunter-wing. Vokunahviing.
"Fire-guiding-Peace": Fire-Guide-Peace. Yolaakdrem.