Sorcerer's Bride

Princess M'lani of the pacifist planet Psyclid, where almost everyone but M'lani is gifted with some kind of psychic ability, has agreed to marry Jason Mondragon, the Sorcerer Prime. Jagan fled their planet when it was invaded by the Regulon Empire, but has now returned, supposedly to lead his people in rebellion against the Occupation. But he's been dragging his feet about it, and when he finally shows up, he has his mistress with him.
If that weren't enough of a problem, M'lani develops a not-so-welcome psychic gift, and then there's that prickly long-time rebel leader, T'kal Killiri, and the antics of M'lani's younger brother, who speaks only through illusions. Freedom for the obscure, peace-loving planet of Psyclid seems a long way away.