Since I haven't invested in the heavy blade seal I had completely forgotten about its existence. Guess I'll have to start from there. Thanks for the advice!
The thing about AoE specials on Lewyn is the risk of getting hit with vantage. Not that high, but it can cripple him if you don't have someone to bring his HP back up.
I've been using this IV in PvE and he demolishes with impunity. Haven't tried 716 range in arena.
Pokemon GO
Fire Emblem Heroes
Fate Grand Order
Dragonball Legends
Dragalia Lost
IV Calc
Heroes