Nihilus is great against any sith combinations. If you gear him, you can make him work at low stars. Use extra to feed him tm. Ezra and GMY will still be your main damage dealers, but with tm buff from GMY, your Nihilus will get a head start to annihilate. You really just need to keep him alive to increase cooldown, then annihilate Sion. Anything beyond that is bonus. The lower stars will make it a bit harder because of lower health/protection, but if you can keep him protected with foresight and restore health/protection with HY, should be able to make it work. May be able to swap out HY for GK or Old Ben for added protection. Won't hold up well on defense, so you may want to swap it out after last battle, but will make your climb easier.
