The buffs aren't really necessary for normal, but helpful practice for when you run vet. If you want the buffs, as a stamina character, you want to do the Blue Arena first as you can't get the buff in the first arena you do. Blue gives the magicka buff, green stamina, red health. Do Blue, Green, then Red. The arenas get harder as you progress.

Therein lies the rub for stamina players, though. Because the most aggravating boss is the minotaur in the Green Arena, which will be slightly harder due to it being the second arena. Its a stamina drain kind of fight more than a DPS race where its more important to keep your resources up and follow mechanics than focus burning the boss. I think its harder than the final boss in many ways, mostly because its laggy and historically bug ridden. But I digress...

You will want to get Shade or Ambush for your stamblade as there is a mechanic on the final boss you need to defeat or its a one-shot. Its a chain of wraiths similar to what you see in Depth of Malatar where you need to kill a ghost to open a hole in the wall or die. Shade or Ambush allow you to teleport through that chain if your DPS is not high enough to defeat one wraith and break a hole in the chain to get out. Or if you want to ignore it and focus on killing the adds outside the chain.

I still haven't become comfortable with this arena as much as the others. The final boss is mechanic heavy but manageable. There are little nuisance adds that I think they could have done without, making it a needlessly frustrating arena on some of the bosses. That, and the bugs just never seem to get fixed, which can torpedo an otherwise strong run.