So you don't think a few BLM/NINs and 1 RDM/NIN could do it in 3 mins? Normal Byakko can be straight tanked by a BLM/NIN with only 3 stuns, and normal Suzaku is soloable by RDM/NIN, so I'm not worried about either of them alone, its just both together. Seiryu and Genbu I'm not worried about.
My plan was, to start out with RDM/NIN RDM/NIN BRD/NIN BLM/NIN BLM/NIN BLM/WHM (the BLM/WHM would be nuking with some enmity- gear instead of damage+ gear to assure they don't pull hate). One RDM/NIN would kite Kirin around while he summons. When he summons Genbu, the BRD would take Genbu and kite him around (without trying to kill). If he summoned Suzaku, the second RDM would take and hold/DoT it. Byakko and Suzaku are the 2 I'm worried about. I'm hoping that 3 BLM/NINs and the RDM/NIN all using their 2h's would be able to kill it before he was able to summon again, thus preventing him from having both of them out at once.
Let's say he summoned Seiryu > Genbu > Suzaku > Byakko which would probably be the worst order he could summon in. A RDM would hold Seiryu, the BRD would hold Genbu, the BLMs would gank Suzaku as fast as possible then get their MP back and then try and kill Byakko before wiping, if necessary the BRD would be able to sac Byakko/Genbu while BLMs recovered. Then the BLMs and RDM would finish off Suzaku, then Genbu.
Afterwards, I'm not sure how to go about killing Kirin. I don't know if 4 SMNs are enough, or if 4 BLMs are better (all of which are capable of kiting when they pull hate), or if 2 SAM/NIN, WHM, BRD, RDM, COR would be the best setup. Trying to figure it out though, but it sounds like RDM BRD BLMx4 would be best.
We're fully capable of going back to town, changing jobs, then going back up to Kirin to kill as well. We obviously wouldn't attempt at a time where people would be waiting to pop.