Twintania - Turn 5. What is it?

Phase 1. 100-80% Ghost + Twintania. Neurolink drops. (Turn 1)
Phase 2. 79%-55% Conflag + Fireball mechanic. Healers need to be wary of Death Sentence. (Turn 2)
Phase 3. Big Snake + Small snakes + Divebombs. (Turn 4)
Phase 4. 54%-30% Twisters + Dread Knight (Turn 4)
Phase 5. 30%-0% Twintania Fight. (Turn 1)

Not going to go into specifics but I do believe each Turn before Turn 5 itself is meant to teach you something in particular. If you really think about it, Turn 5 is literally a compilation of the previous Turns molded together in order to challenge players to put all the pieces of the puzzles together in order to be ready to advance to new content. You already know how to handle each phase of the Twintania fight. It's just a matter of putting it all together.