Hi Mazel, seeing as I've been sending some frequent messages recently, I thought it would be faster to communicate via VM. In response to your question regarding a good Choice Bander, the first thought that came to me in regards to your team was Tyranitar. It has the advantage of synergizing well with Rotom, and can make for a potent trapper of opposing Rotom, which will open up opportunities for Gyarados to sweep. Provided that Gyarados Taunts on the switch, even defensive Rotom with Will-o-Wisp can be trapped and taken out with Pursuit in this manner.