Characters who can conjure up other characters (such as duplicates of themselves, robot allies, elemental or demonic servants, and so forth) can use this power for many exciting and creative purposes. Most of these are simply opportunities for making rolls under unusual circumstances. Examples:
Many of these are Create Advantage actions, either to create a new advantage (Overwhelmed by Conjured Imps) or to discover a specific aspect ("as your shadow-self is disintegrated, it learns that the room is protected by a network of laser beams, and that knowledge is transferred to you").
Characters who can clone or duplicate themselves can use this for concessions in combat ("My three energy clones died, but the real me was elsewhere").
Characters with intelligent allies should not receive extra actions during combat. The exception is when a character buys a stunt that lets them summon NPC allies once per session, for example. The GM should look carefully at the use of all such stunts.