No this game's just balls easy. Yes. Even on the hardest difficulty.
Go to the gym. Get the metabolism workout and you regen faith and willpower every turn. It's not even a challenge at that point.
If you get the 2,000 yen ticket and get a pass for 3 training sessions and you do all 3 back to back, then Richard becomes unbeatable. It increases Max faith. Your faith(HP) in the game also decides how strong your basic attack is, so you can do a ludicrous amount of damage to everything. You don't even need to aim for weaknesses. Your basic attack will do more, and cost 0 energy, while having no ammo cost.
Your soul level, which you can give your demons until they drop to 1 isn't a consideration.
One dungeon dive with the 1.2 exp multiplier and gym training means you can get back to soul level 20 quite easily. Honestly... gaining levels over 32 isn't really all that worth it. If you let a demon squeeze you with the level card equipped and they drop you to level 2 you can get an insane amount of upgrade points, and get back up to 32 in two night dungeon dives.
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There is a secret reverse cowgirl scene that Yami does in this demo tho. To unlock it in battle, you need to get a propensity for hugging and vaginal up to crazy.
Basically it's the fetish system. It's better to not reduce your fetish for anything when working out. It's not like these fetishes will affect the battles any way since the game's so easy.