Anyone else feel this would be interesting?

The idea could be as minor as giving a boss the same set of abilities but randomizing *when* they occur to something really crazy as giving bosses a pool of unique abilities but only grabbing one of them for the fight in addition to what they normally do.

The idea is to reward reaction and quick thinking as opposed to the rote memorization a lot of bosses are now. I'm not suggesting just make it harder, there should also be a flip side such as bosses having a bit less HP or a a few tenths of a second more to dodge abilities.