I agree. In fact, I was just logging in to suggest this same thing.
A few of us logged into Test Center last night to try out the quest. Here are some pointers...
Talk to the Gargoyle Queen to get the quest. Then take a new teleporter in extreme Southwest Ter Mur that takes you across the void river to an area we could not previously access. The ruined town there is overrun with the new demon mobs, which you must kill at least 10 of. You also must find 10 different gargish writings that are supposed to be leftovers from when these demonic forces destroyed the old garg library in this area long ago.
The writings are going to be the hard part as they do not spawn on every demon, and since you have to get 10 different ones I think it will take a lot of trading to get the full set in any reasonable amount of time. On the plus side, all the top damagers of a demon are supposed to get looting rights and kill credit even if not in the same party, so hopefully it will still be possible to work the quest if the place gets overrun by obnoxious spawn hoggers.
As for the demons, they have some nasty tricks.
• 30,000 hitpoints
• Physical 55 - 65
• Fire 50
• Cold 100
• Poison 100
• Energy 50
• They do NOT teleport players to them, which is nice
• Move fast
• Frequently target switch
• Breath fire like a dragon or fire demon, which can do like 80 points but drops as they drop in health
• High wrestling
• High magery
• Dispel frequently (though it's not impossible to use an RC against them)
• Poisoning skill which does lethal poison (cleansing winds failed to cure it about 50% of the time)
• Reverse life leech like Corgul does -- sampires or anybody using a life leach weapon or curse weapon will find the demon leeches life from them, rather than them from the demon. If not for this, a sampire or necrodexer could pretty easily solo them with a feint weapon.
• AOE damage of some kind, but it's not a lot. Mostly makes it target switch more.
Tactics:
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Solo -- you likely won't do this unless you have discord, in which case disco tamers or mystics would likely both do well. I didn't get a chance to try them out on TC, though. Soloing with a regular mystic (maybe even a tamer) would probably be possible but would take a couple of hours.
Groups -- they go down easily with a sampire to kill and a mystic to heal, but the sampire must NOT be in vamp form. In fact, just stone off necro for anatomy to increase damage. Mystic can supplement with RCs. I'd guess this takes about 10 minutes per kill.
Add in a disco, another mage to just cast arch cure (since cleansing winds fails a lot at curing) and then any number of sampires or dragons for dealing damage, and an organized group should be able to tear through these really fast. Should make for an excellent guild activity.
IF YOU READ NOTHING ELSE, READ THIS: I would strongly discourage archers or throwers from going at all. When an outside shot comes in the demons love to target switch and chase, which causes all sorts of chaos and makes it nearly impossible to keep dealing damage to them. Mages that go should stick only to healing and summons, never direct damage, until word of death range. ALSO, sampires (and any other direct melee fighters) must use a feint weapon and keep feint up all the time, or they will likely be dead more than alive.