I played it last night for a bit. I got to the Wendigo fight (the first time you actually have to fight him yourself) and got my ass kicked twice. That son of a bitch was killing most of my demons on one or two hits. It seems like this is a GRINDAN game, unlike most SRPGs (with Nippon Ichi's games being an exception; they're nothing but grinding).
What level were people at for this fight? IIRC, my three human characters are about level 8, they have two demons each and while a couple of the demons are level 8, most of them are between 4-6. I have actually grinded (ground?) on about 4 random battle so far, too.