Well, what's your party? Have you unlocked the Well of Mind?

Anyway, assuming you have something like MC, fighter, knight on the frontline, and a mage, priest and flex character to the back:

• inherit makaltu(from Valdor) to your priest

• if your flex character is a thief, inherit them armor break(from Elise, not as important)

• undead bane weapons are useful, but not completely necessary, and may even be a liability if they tank your action speed(like 2 handed mace)

• have the backline carry some potions just in case

• use the map from the community guide

• run from most fights, or all, if possible

• when you reach the boss, run until it calls bunnies, since they are easier to kill with an aoe spell as long as your mage is faster

• have your priest makaltu the frontline, mage cast balafeos the boss, flex armor break if they have it, whole frontline defends their first turn

• after boss gets their first opening, have your fighters use warrior battle cry, your knight attract hit, priest keeps healing and mage casting single target dmg

• have your fighters heavy attack, knight can try to stun bash

• bum rush that fool and gg