<Snipped quote by Flamelord>
All Tatsunoko has to do is think. INSTEAD he's reveling in power.
I would agree if we weren't talking about Tatsunoko.
He doesn't go for the obvious choice, forbidding his servant from attacking him, as that wouldn't make him obey either, and with 1 command seal left he would just be a leech. Letting him suicide seems like the most relevant choice at that time if he were to use a command seal.