Volan is the last boss in Infinity Gate. To be able to summon him you have to defeat Breaker X-1 and the Life and Death brothers.
He is worthy of being a last boss and although the DPS check is not as tight as it should be, Volan is still a great encounter. I think that if he would have 1 more 5 minutes phase he could compete with Akylios for the title of “Most awesome boss in Rift”.
Volan is a cool fight for the tanks and the healers. Not so much for DPS, but they get their fair share of mechanics to watch out for and dodge.
Good luck !