As far as I can tell, killing Bixt completes the zone, but spawning Bixt requires killing the same mini-bosses as the Foresight of Farseer quest, so you might as well do both at the same time.
Details about the mini-boss fights are in the Foresight of Farseer quest post.
After Zuru is killed, npc Ghillie spawns. Chat her and a pretty graphic sequence will occur which ends with a portal being created on Zuru's chair. This portal takes you to the Bixt Room. Oddly enough, toons can be CoHed to that room without needing to run to the portal.
Bixt is the only mob in his room. He is not rooted, he Enrages and Rampages and Wild Rampages, and he has a knockback the flew my tank about but did not effect my other toons who were about 20 feet away. He also casts something that does AoE damage that might cover the whole room but I don't know anything else about it. During the fight, there is a color graphic sequence that has cubes spawning and tunnels of light going back and forth between them but I don't know what effect they are supposed to have.
When Bixt dies, another Ghillie spawns. Chatting her will get you one each of Livi's Rainbow Cake (item 922147) and Livi's Rainbow Juice. Everyone in your group can do this once. Ghillie will eventually despawn.
If you want, you can zone out and chat Ghillie in the Glade to zone back in again. If you do, you'll see one of two things:
1) The zone will be as clear as you left it, with the exception of ONE respawn, whose static spot is at the south entrance of the Incubator Room. Plus, there will be a Bixt Portal nearby. If you use this portal, you will find that Bixt is alive again.
2) No portal, but Ghillie will be there such that you can seemingly repeat all the mini-boss kills. And as mentioned, the zone will be as you left it except for the addition of that one respawn.
If you get the second Bixt, that fight and the subsequent Ghillie will be the same as the first time. It will not repeat for a third time though.
I don't know what happens if you repeat the mini-boss killing. I've not bothered to find out.
I also don't know if this situation is as intended or if its a bug that Lillu will fix as soon as he reads this post.
