If I am not mistaken Mighty Majin already has an taunt skill, in the 70lvl patch they added a very similar, just longer taunt skill to the Ultimate Majin skill tree. I find it very useless.
Besides buffing, debuffing, supporting & transforming into Kid Buu, Ultimate Majins know to be pretty useless and passive at later levels (depending on build).
They are pretty tanky tho, so here's my suggestion. If you guys could remake the single target taunt from the Ultimate Majin skill tree into an AoE one, that'd be great.
They could control the aggro and lessen the work and worries of the party in general besides sitting there spamming heal & cures.