I take a normal team, and if they die, use Selena. Level 2 of them all is kind of a pain in the ass.
For my light mecha, I took Selena (lead), Tridon, Shera, Ulkina, Arus, and a Lilly friend. Even with all that defense/healing, I lost Arus and Ulkina at one point, and Selena had to burn her...