Control AI and become AI

Hi i am new and all and have played around for awhile but i am wondering how would i get my main character to control any ai and then come back to the main character when done with whatever. And also was wondering how would i do a
destroy all humans type effect where he can become any of the ai from afar. Any help would be amazing. I do not understand some things like how do animations and effects get added to certain actions.

Thank you!!
Happy New Years.

This is some tutorial about possesing pawns:
https://docs.unrealengine.com/latest/INT/Gameplay/HowTo/PossessPawns/Blueprints/

For your game you need to make 2 controllers: one player controller and one AI controller. Then you create events to posses and unposses pawn in both controllers. When you want to switch pawns (character) you tell player controller to unposses old one, and posses new one. Then you tell AI to posses old one. This way old one becomes AI bot, and new one will be your player.

I also done similar stuff but different way. My player pawn was just camera that attached to character. All characters were AI. AI controller was tracing where player camera pawn is attached to, and for one with camera was sending WASD keys over instead of normal AI stuff.