You’ve learned to summon a more diverse array of monsters.
When you summon one or more creatures that would normally be available with the celestial, entropic, fiendish, or resolute template using a summon monster spell (or an effect that mimics such a spell), you can instead apply one of the chosen templates to each creature. You can apply a different template to each creature you summon.
Special: You can select this feat more than once. Each time you do, you can choose an additional two templates.
Pathfinder Player Companion: Monster Summoner’s Handbook © 2015, Paizo Inc.; Authors: Alexander Augunas, Tyler Beck, Anthony Li, Luis Loza, David N. Ross, Owen K.C. Stephens, and Linda Zayas-Palmer.