Supremacy
A good mastermind knows how to manage his Henchmen.
A mastermind gains followers from the Leadership skill, and these followers are more devoted and the mastermind more crafty than normal in getting to have them around. This means that a Mastermind's followers are always around when he wants them. A mastermind can instantly replenish his stock of unamed followers at the cost of a Magic point, and can call in a replacement for a fallen named follower at the same cost. This is a 3-shot action.
Masterminds often have several identical named henchmen that they call in as replacements in combat.
Build
Obviously the Leadership skill is a must, and several pulp schticks go with it.
Besides this, masterminds tend to use Sorcery skill and Sorcery schticks, using these powers to support their troops.