ToME: the Tales of Maj'Eyal

on my new alchemist i found this maul yesterday and the maul matches the tier of the used gem.
it doesnt get fixed to the first gem you put in.
yes the description is lacking, only says it can be enhanced with a gem

so on my steam account i have achievments i dont have on my tome account( most importantly storm tree for the archmage), i know i can sync it so that steam gets the achievments one has on his tome account but i have the problem the otherway around.

it is unlockable wether or not you have storm.
the category point for it is from my viewpoint too expensive.
if you want damage go for fire, if you are a golem player get ice.
why would you pick storm? it really baffles me.