one is the fatal crest, which you can get by beating the first 4 hades cup by talking to pain
the other is ther ferir blade you get from beating sephiroth. HE IS MAD HARD. leval up as much as possible! you'll want reflega other magic DOES NOT work on him. he is at hollow bastion:dark depths, 2 areas after crystal fissure, dont bother training your drives, you'll be fighting him alone.