This is the way how I as coercer made 7 levels in one single day, with two friends in team afking with autofollow on me:
During night some kind of event mobs spawn at the southern road of New Tunarea. They are vampires which will attack any elf mob on sight and nuke for a constant amount of damage of at least 18k (30k crits). So all you have to do is charm one of these vampires, set /pet ranged and clear the whole elf camp. You will be able to kill every single dark red ^^^ with solely two hits, which will also get you a nice amount of cash (four master drops due to the fast ^^^ kills in one day). A single ^^^ fight will take ~6s. As mentioned, this will solely work vs. elves, all other mobs are immune to their special ability. But that's not much of a problem since the camp is crowded by elf mobs.
Even though it is definitely not intended that these mobs are charmable, you don't break the eula in any way, so no need to worry for getting banned by powerleveling.
EDIT:
Ok, I will now try to explain it better:
1) This is performed as coercer with Master I charm - it does NOT matter what level the charm has, it is much more important what rank it has. So level 47 Master I charm will do much more damage than level 61 Adept III charm. I don't know anything about necros, so it might be the case that their charm isn't as strong as the one of coercers. However, as coercer I can confirm that the vampires kill any ^^^ elf with two hits with M1 charm, which is ~4-6 seconds to recast=~6 secs/kill.
See screenshots: The dot that's on the mob ticks every 6 seconds:
Pic 1=chatlog, Pic2+3=fight of chatlog, so one tick in between both nukes. As you can also see, it is a constant damage at every mob:
2) Set the pet on /pet ranged. This will make the pet go melee ONLY when he is close to the opponent, so all you have to do is keep the mob away of you by rooting/stunning/snaring or whatever so your pet will nuke whole time instead of autoattacking.
3) Most vampires solely spawn during night. An exception are the ones at the southern road - they are here during day instead. There are a couple of different spawn locations, see map and screenshots for two: (there are more though).
Location 1:
Location 2:
Last some other random fight pics:
![(!empty($user->lang['IMAGE'])) ? $user->lang['IMAGE'] : ucwords(strtolower(str_replace('_', ' ', 'IMAGE')))](http://img187.imageshack.us/img187/7453/fight3zm0.jpg)