Nope, you convert the flavor of the power to work with the creature.
Instead of blinding barrage getting blood in the eyes of ghosts, have there be so many blades going through the ghosts's eyes that the phantasmal goo with the ghost's eyes are made of disperse from its being for the same duration.
Reflavoring powers is one of the most important skills necessary for excellent 4e DMing.
Fully agree.
Our ghosts heads are temporary destroyed by blinding barrage, reforming a couple of seconds later.
