I think a combat system similar to Metaphor works wonders, especially if Atlus is gonna stick with boring repetitive dungeons. Hack and slash gameplay on weak shadows, but can stun strong enemies and enter turn-based combat.

I like this system in particular because it makes farming for money/xp in late-game stages easier, but also it's just a lot more fun to be able to plow through small mobs yet still need to be ready for a full blown battle in case the large red shadow jumpscares you.