After you've completed the 'Saving Scarlet Robe' quest, you can walk back to Cliffside Path, where there will be a total of TWO Undead. Despite the fact there is only two of them, they will respawn infinitely upon death (or so it seems at least), and the second wave will be targetable almost immediatelly after the first ones have died.
I had Enflame 4 and just kept spamming it, got bored at 155 CM, but had enough exp to max out the character anyways.

Watch it! It's NOT Clifftop Path that takes you to Twinblade's Camp from Oakvale, but the other one, between Lichfield Graveyard and the prison!