Lvl 121+ PvE
MrT/Wit/BT (or Cannoneer)
Assuming you want full AoE formation for the endgame. This is of course not really that ideal, endgame PvP needs a Cannoneer somewhere. You can arguably drop MrT for the Cannoneer, which most do, but then you need another monk somewhere...
Still, the above gives you four usable AoE's: Flame Blow, Powersaw Raid, Beast Summon, Meteor Strike.
It must be said however that for endgame PvE, the AoE formation is very weak. If you're at the stage of the game where you're taking content in Lijang Women's Village or higher, AoE becomes largely worthless. For expansion content (post Adlivun), Aztec, Dallas and Detroit mobs are very phys resist, very magic weak so AoE rapes hard there. But for the rest of the endgame all the way up to the absolute end in Coyote, AoE is largely worthless.
Tier 0 lvl 121 StaffM form:
Spa/StaffM/Nvik (or druid)
Option1 and Option2 can be combinations of Oracle, Inventor, Elementalist, Witch, Janissary or Hwarang. Pirate isn't really used. You have two 'option spots', the rest are considered essential if you watch any Titan final with Staff mains.
It also must be said that if you plan to PvP at the highest tier, your Flame Blow needs to be lvl88. Which means lvl70/70 Flame Blow naturally, lvl120 Charm for +15, and Ruby necklace for another +3 magic levels.
If using a Druid, then drop one monk and add the Oracle as a must have... The metagame with a Druid completely utterly changes. From there, unless your opponent has a Druid as well, they are on the back foot at a disadvantage from the immediate start. Their immediate goal will be to try and stop Wolven Seth. If they cannot, you win by default, end of story.