Kefka Sucks. Kuja Is Better

[The Crystal]

You're still missing the fact that keeping Kefka around was, far from actually helping the Emperor achieve his goals, arguably extremely detrimental to the Emperor's case. It would have been obvious to anyone with half a brain that Kefka was a loose cannon who was liable to go off at any time. But the Emperor doesn't give a . It should also have been obvious to anyone with half a brain that Kefka's presence could very easily be argued to inspire rebellions that arguably would not have happened if he had been locked up the way he should have been. The Emperor was quite certainly evil, but he never caused suffering that did not directly contribute to his goal of accruing more power for himself. If he caused suffering, that suffering was simply a byproduct of the fact that he wanted to control the entire world. For Kefka, it was obvious from as early in the game as the poisoning of Doma that causing suffering was the whole point, for one thing because we see him he explicitly admit as much right before causing it, but even without that clue it should have been obvious - his soldiers get that he's extremely screwed up without ever having seen him admit as much. Having someone who's ostensibly on your side going out with the sole goal of causing suffering is a lot more detrimental to one's cause than simply having suffering be incidental to the accrual of power. If convincing someone to give you free rein to do basically whatever you want when your actions are repeatedly clearly detrimental to the cause being advanced isn't manipulation then it's obvious you just have a different definition of manipulation than I do.

And I never said Kefka manipulated more people than Kuja did. I simply said that your argument that he does not manipulate people is false.

Did it ever cross your mind the reason Ghestal kept Kefka by his side, was because Ghestal needed him? After all, Kefka was as cruel as him(probably even more), and wouldn't object to some of his more morally ambiguous orders, like the honorable Leo and Celes would. Ghestal needed Kefka to do the dirty work no one else would agree to do.

Or it could be exactly as you said.

In the end, we don't know the real reason for Ghestal to keep Kefka by his side. It was never revealed in the game.
Therefore, you cannot use it as evidence of Kefka's manipulation skills, because your evidence is speculation.