Nice sarcasm Cerb

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Au contraire Evilsod, I have no problem aggroing 3 groups (7-9 aatxes, depending on spawn) and killing off anywhere from 1-4 nightmares all at the same time. The problem with the necro killing them, is that he then has to be in the same aggro circle as the nightmare, and thus likely the same aggro as the aatxes. If you (the monk) are still running around grouping up aatxes, then they are quite likely to turn around and attack the necro if he's close enough for them to see. You should be killing nightmares as they pop, not after you stop and have all the aatxes around you. A monk shouldn't take a line that he can't handle on his own, if he can't kill 3-4 nightmares by himself, he should be taking a slower line until he's more experienced.