Been thinking about the boss fights some more. I'm not sure Retaliate is the way to go for Anima. The arm you leave alive you have to keep Magic Break on it or else it's AoE thunder will do too much damage. As you continue to use magic break on it though, you will damage it, which causes your retaliate target to switch to the arm soemtimes. It's very annoying. To make matters worse, there's a good chance that your retaliater won't be all that strong. I had Cloud yesterday doing about 1200 per hit non-boosted. If you have someone stronger it seems best to just keep Power Break on the boss and let the other person double cut him directly and eat the counter attacks. If you have Protectga (and everyone should, after the Lenna event) his counter attacks won't do that much damage, and if you get unlucky and get the double Anima fight you can alternate Protectga / Power Break to make sure you have some juice left for round 2.
This is how Anima works:
- At >50% HP, attack mode. Arms will hit someone every time their ATB bar fills up. Anima counterattacks anything targeted at him
- At <50% HP, magic berserk mode. Arms will wait for the 'magic resonance' (or whatever) dialogue box
and wait for entire living party's ATB to fill up and then AOE thunder. Anima counterattacks anything targeted at him
- At any point, if both arms are dead, Anima will take either 2 turns (>50% hp) or 1 turn (<50% hp) to regenerate his arms. In this state, he doesn't counterattack, but that's a moot point considering how short a duration this is. He also takes slightly less damage because he has slightly more stats for whatever reason while regenerating his arms.
Essentially, then, there's 2 stages to the fight. You shouldn't be touching the other arm with anything until Anima is below 50% hp. THEN you hit it with Magic Break, and that should be the first thing that damages the arm, and its HP% will still be higher than Anima (unless your Magic Break hits for 7k or something lol)
While I've killed Anima on heroic only twice (in the same run Jesus), the total attempts on the first kill was nearing a dozen, and I never had Retaliate hit anything other than the main body (unless I screwed something up)
But yes, Protectga + Power Breaks are another completely legitimate tactic to unload your strongest abilities on him and tank the counters. Preferably if you have Kirin or Lenna soul break.