You can sacrifice his A-skill slot for Attack +3 or his seal for Attack +3. But if you don't want to do that, I suggest you try again for a better IV one.
I think I'm going to try for another one, though I probably won't get it. For now, I'll give him the Attack seal (and maybe Deathblow/Fury/LnD for good measure).
Pokemon GO
Fire Emblem Heroes
Fate Grand Order
Dragonball Legends
Dragalia Lost
IV Calc
Heroes