Final Fantasy ... again somewhat the same thing?

You can steal star curtains from Dark Flan which you'll find on Mount Gagazet, or you could just cast reflect on him to stop him healing himself.

Despite his semi-low HP, Sanctuary Keeper is one big bastard. He casts a lot of white magic on himself, and may get on your nerves casting multiple Curagas. Make sure you have Esuna ready, since his Photon Wings attack inflicts multiple status effects on all your characters, including Confusion and Darkness. First things first, cast Hastega, then have Auron use Armor Break to penetrate Sanctuary Keeper's defense. While he's in this state, he won't do much except continually cast Photon Wings and his weak-*** tail attack. You might want to get Lulu out as well as Wakka and/or Auron. When

Sanctuary Keeper casts Protect or Shell, just use Dispel. This will cure Armor Break too, but it's not hard casting it again, is it? Now, his Curaga heals him for 9000+, so try not to fall back and mess around. His worst is Regen, as it will heal him 1200+ every single character move, so get that Dispel out quickly! If he just keeps on casting Curaga or Regen, just reset. Keep on trying if that happens, and you should eventually beat him.

Hope this'll get me best answer.......