Ok, here's my evil counterparts to the Star Sisters, The Shadow Sisters!

They were three Horde Force Captains that found great favor with Horde Prime, so he sent them to Etheria and gifted them with new powers and abilities to succeed where Hordak failed in conquering Mystacor, Brightmoon and The Kingdom of the Snows. However, they turned against The Horde and set their sights on taking Castle Grayskull so they could rule the Universe.