Lycanthrope
Mabinogi: Lycans level up after a knockback, meaning that they will heal, the only skill that doesnt make them level( Mabinogi powerleveling) is windmill, so the best way is to spam WM, they are really slow so you shouldnot have any trouble wm spamming these, specially since your with a party here.
The succubus
Succubus for normal and basic have the same AI, red just haves more HP(mabinogi money) and dmg. Beating human-speed bosses is quite easy once you get the hang of it. You can just spam firebolt or magnumshot, or even smash, for smash you have to stay close enough in case she casts, but far enough so she does not hit you. The easiest way is probably fire-ice-counter. Even if succubus has mana refractor, her speed lets you counter in time if she's in the right distance, thats why you use fire.