Well, when they were first introduced in beta, Skrees used a wide variety if not all of the Mysticism spells, including Rising Colossus. The major problem there was the Rising Colossus, because after it killed the target the Skree wanted gone, the RC would aggo the Skree, or you! LOL.
Okay, I've been wanting to write up a pet balancing idea for some time now (Reptalons and Skrees come to mind, but haven't had much taming experience with Iron Beetles), which is why I ask.
I wondered if they could make a dolt of a Rotting Corpse, for example, so that another pet could train easier, but then, the nature of sleep, and how the next hit counters the purpose of the spell, sort of defeats the purpose.
Perhaps if the Skree could cast sleep against non-primary targets around it, rather than it's initial target; crowd control, hehe. Not sure how hard that would be to code, plus, the base DI is still rather low.