Board Thread:General Discussion/@comment-44061-20130307153642/@comment-10587310-20130918232136

No not their powers. But like when the the hollows go from being a Gillian to an Adjuchas and eventually to a Vasto Lorde. They eat other Hollows to increase their own Reiatsu, Reiryoku strength, speed, Endurance, and Durability. Until they can evolve. Like how Ichigo's Hollow form changed. Over time His inner Hollow/Zanpakutô spirit could have been "eating" the hollows he defeated. And that helped him to Change because they are a part of each other they supplemented each others growth rate.