I couldn't finish 'em. Looks like this's gonna get complicated.
Kain, stop this!Rosa
Rosa is a boss from Final Fantasy IV: The After Years. She is fought in Kain's Tale, at Damcyan castle, when Kain's dark side tries to steal their crystal. Edward accompanies her in the battle. She is also fought in a flashback at the end of the Lunarian's Tale.
Kain's Tale Edit
Due to his feelings towards her, any of Dark Kain's attacks that target Rosa will fail, but the battle is scripted, and the player only needs to attack Edward a few times to end it.
Lunarian's Tale Edit
The encounter is a recreation of Golbez's fight against the party at the Dwarven Castle. Rosa will buff members of the enemy party with Protect and Shell while they attack Golbez. However, due to their minimal damage output and their high HP, it is impossible for Golbez to kill any of the enemy party or they to kill him—the player just needs to fight until Golbez summons his Shadow Dragon, ending the fight with a cutscene.