It is recommended to kill these creatures in groups, due to the fact that they heal fast. Try to use all of your mana before facing them, as they will quickly drain it away from you. Mages: Mages of level 45+ should use 1-2 SD shots fast on these creatures since they heal a lot and have a very strong mana drain which would be more expensive than the SD runes. Knights: With 75/75 skills and level 40+ you can let them run in a spot where they cannot move (like the treasure room entrance in circle room) or a corner then melee them to death, before they run into a bunch of other creatures. Paladins: Level 40+ paladins should run with bolts and maybe Icicle runes.