Kefka did what he wanted when he wanted how he wanted. =]
With no thought of what would happen, what so ever. I'm sure in Kefka's life he had no doubt about anything.

We all know Sephiroth had his crazy doubt moments with Jenova and what he was and what not, Obsession led Sephiroth to insanity.

Experiments led Kefka to insanity, but that makes me think.. because Kefka was prolly crazy -before- the experiments as a child.

Now now Kefka, Don't put arsenic in Leo's sippy cup... and well.. yeah. You get the picture. >=]