ok so after killing teh Mission version i went along with 5 other people to kill the Prime Version
Party Set up:
PLD/WAR (me)
WHM/SMN
RDM/BLM
RNG/NIN
RNG/NIN
BLM/WHM
ok first run we got killed early on got it down to around 80-85% this was our "dry run" just to make sure nightmare etc could be stunned
The Real Run, went really well, i jumped down and dragged him to the top right corner, mages & rng were at bottom left corner, (out of sleepaga range very important) during the fight he spamed sleepaga 2 around 5 times and he casted very fast, i assume he is RDM type mob, with Fast cast etc, the fight was going well he 2hrd around 20% HP which must have took around 75% of HP off as everyone was down to around 100hp this scared the hell outa me which made me 2hr, shortly after the whm ran in with beneditction then the RNGs,RDM & BLM all 2hrd and he went from 20%-0% in a few seconds victory!
I think nightmare didnt get through but may have gotten through at the end when everyone went made & full out, who knows >.>
A manaburn is not needed to beat him, RDM/DRK for 2hr stun is not needed, PLD can tank him fine, & RNG still dish out the damage.
Meds used: Hi-Potion, Hi-Ether, Tacos. (note no use of posion potions ~ on my server theres a rumor going around that they reduce the sleep time of Nightmare)
All in all, easy fight just make sure that mages are outa range of Sleepaga.
Cold