But he does gain the attributes of his victims. If you want to get better at say shooting rifles or driving tanks then you devour people who shoot rifles or drive tanks, gaining their skills as you go. That's part of why I've been trying to find a way around the Illithid only pre-req of Illithid Savant. Also, if I could ask for some clarification on the Greater Doppelganger: if I eat a level twenty warblade when I change into said warblade do I then have access to all of his feats, maneuvers, stances, etc.? In addition to or instead of my own class abilities and feats?
Also, can't an Egoist turn into an Aboleth via Metamorphosis? Would this allow you to pick up the feat, Memory Eater?