It's not actually that hard, remarkably easy, and some hard enemies are even easier now. Spam Z until they die, if they don't walk back, get some stamina, if they close the gap dash through and keep walking, mix in the occasional X even if it's a trash option that isn't worth the stamina cost. If you need health, just farm a room or two, your stamina regens faster after a grab, so sometimes letting yourself get grabbed for Stamina is a decent idea, albeit the con to that is you trade some health.
Now the gun, *the gun is hella useful* for comboing into attacks as a finisher. Ora Ora them as Sam (the better of the two characters in combat now) and then shotgun them, it's great.
Of the two, Sam's came out strongest from the update, her Ora Ora Z spam is multiplicative times better than Whispy's double sided hitbox- the point I think is that he's supposed to use his knockback X to corral them into one spot then walk up and Z spam but nobody has enough health to make that poignant as an option, Sam's X as the occasional long stun can help way more than Whispy's X smack.
Notably too, Sam's attacks are...faster? She can stunlock some enemies that are supposed to get I-Frames after you beat on them too hard, unlike Whispy.
Though, I suppose it makes sense Sam's the more combat capable of the two, given she's the proper hero, neat stuff.