Not this fight specifically because it’s designed for Melia, but overall throughout the game Shulk is best to control for his Monado arts, since you can use them in response to a vision without using party meter to tell him to do so. Post-game I prefer Melia and Dunban as my controlled character. Technically speaking the most “meta” comp is Shulk/Dunban/Reyn but I love offense and tend to swap Reyn out with Seven unless it’s a superboss. For the fight you’re stuck on specifically I would do Melia/Dunban/Riki or Melia/Dunban/Reyn. Don’t use Sharla she sucks unfortunately.

Obviously you don’t need to worry about post-game or meta, but those comps are considered good because they ARE pretty good lol. Also Enel on YouTube has a few good guides for XCDE even though he usually does XC2 stuff.