Armamentalists learn M-Pathy after putting 68 points into the Force skill tree. It costs 10 MP to cast and grants 100 MP to your other party members.
M-Pathy is known naturally by Estelle at level 1 and can be learned by Gold-plated puppet level 44 and costs 60 MP to use. It has a range of up to two squares away from it in any direction and restores a minor amount of MP to the target ally. Upgrading this skill increases the amount of MP restored.