This is a downloadable boss fight for the Coliseum. When you visit, the first fight will just be against Lightning. After you get her most of the way down, Amodar will join the fight. I personally found Amodar far more devastating. He uses grenades that hit everyone and are likely to bounce you up in the area. He hits hard too. I like to focus on him first. When you take one of the enemies down, the other will gain access to their six bar special move (like Lightning's Army of One attack). This is a fight that doesn't respond well to using Syn or Sab so I would recommend that you just plow through and heal when you need to.
Both enemies can be tamed and put in your party though neither is guaranteed. Lightning is a Ravager with 13 levels. She's very good as a Rav and when an enemy is staggered, nailing her Army of One can really boost the gauge. Amodar is a Commando. He's good as Commandos go but I'd probably still stick with your Chichu.
