What is the Seirenia quest? I see that she's in a pond of some kind and she'll fight and kill you and something about her clothes.How do you get this quest?

The quest initiating item drops from the Grove Abex,"Namus's Diary." Something to that effect, it should prompt a screen anyways when you try to pick it up. :3 If you do get it, run as fast as you can back to the NPC, because she will 1-hit you if you take too long.

Thanks.I also asked my legion about it.Its better to do it at night

She only spawns at night, game time that is. Not until after 7:00 PM game time. Once spawned she will remain there for a bit, and if someone else grabs the clothes they reappear pretty quick, so you wont have to camp for days on this.

Just before I ascended I went back for some revenge, and she was STILL red. So unlike other Named mobs you may go back to avenge yourself upon, this is not one of them.

Be aware that this is not a 'sharable' quest, so you MUST get the loot item to do it, and your groupmates will also have to get it independantly.