I played Nocturne on hard and I apparently got lucky with the tutorial, only dying like once. Aside from some bullshit ambush garbage that you don't have the means to deal with early on, the difficulty was pretty fair. One problem, though.

Hard Mode doesn't just change damage numbers and enemy ambush/crit chances; it makes EVERYTHING (barring the healing shrines) COST 3x AS MUCH AS IN NORMAL MODE. Now, I'd be fine with it if it were just standard healing/status/damage items that were affected, but it ALSO increases the price of the Magatama you buy in order to ACTUALLY GET SKILLS. In other words, the game straight-up punishes you for experimenting with your build by forcing you to grind, which goes completely against what the game's difficulty curve seems to be based on: fighting only the random encounters you get when going from place to place, rather than specifically seeking them out.

Long story short, do NOT play Nocturne on hard mode unless you like grinding, or looking up guides on how to minmax your character. I've heard there's a hard mode romhack that balances it better, though.

Admittedly yes, but if you buff and debuff he doesn't do that. Especially if you buff evasion, since missing removes his extra turns.