ToME: the Tales of Maj'Eyal

I know there's dagger mastery, weapon mastery (swords, axes, and maces), and exotic weapons mastery. What I'm not sure of is where greatmauls fall. I'm assuming that they're either an exotic weapon or considered a two handed subset of maces but I'm not sure which.

Two-handed swords, maces and axes all use Weapon Mastery, as well as their one-handed counterparts.

Exotic Mastery is for whips and tridents. There are only a handful of whips, and they are all fixed arts. Tridents drop from naga NPCs, and there are a few fixed art tridents, too.

Also what is intended to be the best weapon in the game is a trident, but you need to spend a prodigy for it (legacy of the naloren).

Also, most of the whips (all the one handed ones) can be wielded in the offhand like you can with daggers, shields, and the bottom half of the staff of telos.

here is a list of relevant exotic weapons: Legacy of the Naloren

If you hover over a weapon, somewhere in the tooltip it will tell you which mastery it uses.