Ring event. Power drain. The first two rings, kill the mob in the group you are in (it is in red in your chat window). The mob's name matches your group. The second fight is a dps check. Kill the color golems you get in the third ring. They will swap names at a certain point and you need to quickly switch to your new mob or you will wipe the raid. You can CA/Spell AOE as long as you are targeting your color golem. Cure curses or it may wipe the raid.
EQ2i credits EQ2 ZAM for some of the info in this article.