My top 3 places:
Past the teleporter there is this room:
You can lure as many vampires and gargoyles you can fit, to enter this room you just right click the wall besides the golden scarab outside the room and to close the room you do the same besides the golden scarab 1 sqm above the character in the screen.
You just maneuver every monster around in a way where the Mad Sheeps are the ones attacking you and you can shoot small stones at the vampires and gargoyles.
This spot also works great for knight but you cant lure vampires because they have magic attacks that are unblockable, just lure as many gargoyles you can, when they are weak they will run away, giving space for a new one to start attacking you while they all can heal.
POH for Paladins
There is 1 vampire and a spot where you can trap him and leave the mad sheep blocking 1 sqm, so the vampire cant pass and you can just shoot small stones at him from a distance.
This spot is unlocked when you finish the Shadows of Yalahar Quest. It is a room where there are only Modified Gnarlhounds, they are passive monsters with a lot of armor, a lot of resistances, decent hp and can spawn even when players are there. Because of their resistances and armor its almost impossible to hit them normally so you might need weapons with elements.