Have you guys given any thought to trying this out? It's an interesting encounter, not to mention some pretty nice gear drops throughout it.
The ring of fire was removed from Acrylia in the zone update of April 2003 
Yeah, I just found out. =/ Oh well, at least I got to do it once before Sony gave it the nerf stamp.
i wish i could have done that one. =(
There are other ring style events we could try.
I've been itching to try the ring event in CT.
there is a ring event in UP too, similar to PoJ Execution TrIal, just not timed. 4-5 rounds of 4 Aliens each. After those 5 i think each round then starts spawning 4 Aliens + a Boss Alien. There are 3 Bosses i think and each drops nice loots. We REALLY need to hit UP more to start upgrading our guys. Good stuff there and not all that hard. 2 Balanced groups OWN those caves.
/agree Grriffon
UP is nice zone for us. Minimal numbers required, fast hunts possible, decent loots to be had. We did one of the aliens on Wed night. Once we actually got to hunting in the caves, it took under an hour to finish off Spirit of Radir with 10 of us.
