Hard to say something decent about this idiot fight.
Pretty much Its Mysterious Figure. There's no 100% sure fire strategy just prayers.
Pretty much as Aqua the main strategy is to Dodge and Poke till dead.
Although MF takes no damage from any Mine type spell. MF will still dodge it by jumping over the mines set.
You can use that to your advantage to attack and heal freely. If you use a D-Link MF
will go invisible regardless of his life. Surge spam isn't 100% sure-fire win as he can still block or stop time on you.
Pretty much the Surges only real use is killing the clones efficiently. If you're caught by his rope
9 times out of 10 you're dead cause the follow up attack will catch you and you're still recovering.
So that attack generally ignores Once More ability.
MF's attacks are worse on Terra for some reason despite having Both Second Chance and Once More abilities.
Most of the attacks just mean instant Death for Terra.
Shot-Lock Spam may work but there's a risk of MF blocking it. Even if you have under 5 locks.
Finishers also fall under this as Mysterious Figure may randomly block it and generally restoring all his health.
I don't need to bother to mention Renew Block/Barrier as its generally the only effective guard ability in the entire game.
Ice Cream can be effective if you have the moment to use it. As well as not having your finisher blocked.
Especially since some command styles absolutely suck in mobility, Defense, or Attacking.
Command Style Changing is a bad thing for this fight. Usually it'll kick in when you don't need it.
(when you're dodging or taking damage mid-combo) So often it'll lead to your death.
The glitches this Super Boss has is ridiculous. Generally they're all in favor of Mysterious Figure.
You can get one to work out for you but either way its a glitch.
FYI: Critical Mode on this fight doesn't really change anything about it. Just a little less damage and less Lifebar which doesn't matter cause he'll still knock you down to 1 HP in 1 to 2 hits. LOL. If you beat this guy on any difficulty you completed the game on Critical LOL.