Reflective Charm?

[Patryn of Elvenshae]

So if a caster casts dominate person and the spell is turned back on himself...what would he act like? being self-dominated and all.

Pretty normal. After all, he already obeys all his own mental commands to the best of his ability.

You can control the actions of any humanoid creature through a telepathic link that you establish with the subject’s mind.

If you and the subject have a common language, you can generally force the subject to perform as you desire, within the limits of its abilities. If no common language exists, you can communicate only basic commands, such as “Come here,” “Go there,” “Fight,” and “Stand still.” You know what the subject is experiencing, but you do not receive direct sensory input from it, nor can it communicate with you telepathically.

Once you have given a dominated creature a command, it continues to attempt to carry out that command to the exclusion of all other activities except those necessary for day-to-day survival (such as sleeping, eating, and so forth). Because of this limited range of activity, a Sense Motive check against DC 15 (rather than DC 25) can determine that the subject’s behavior is being influenced by an enchantment effect (see the Sense Motive skill description).

Changing your instructions or giving a dominated creature a new command is the equivalent of redirecting a spell, so it is a move action.

Since the first instruction he'd give is, "Act normally," he wouldn't need to change commands all that often.