So I wanna go on a Strange Journey, but the Demon Fusion system seems quite overwhelming...

Also, people hated the encounter rate that much? It was definitely a pain at times but I always loved to get AP/JP/points that get you new skills/spells in RPGs, so it didn't feel that bad except when I wanted to backtrack.

I should replay it.

I would say that SMT 4 is the easiest SMT game,its pretty easy to break the difficulty by giving pretty much all your demons luster candy and other high tier abilities since you can choose what skills pass on.

All of them

Except Persona

Already did its stated that the Great Will got tried of YHWH shit and got Nanashi/Akira and Flynn to go kill him. YHWH went crazy because he was lonely and had no one which is the official reason why he's an asshole. Demifiend in the Stephen DLC canonically loses to Lucifer and has to get his jobber ass bailed by based Stephen.