Hades is the renowned and reclusive ``Master Synthesist'' of FF9. You encounter Hades in Memoria, in the room where Quina thinks she is swimming (see Memoria script for the exact spot). Search this room thoroughly; towards the back there is an area to the right where you can wander around but not see your character. Hades resides in here; you will not get an ``?'' or ``!'' when you encounter him, so you will need to keep pressing the X button until a dialogue appears. A ``mysterious voice'' will try to ward you off; if you continue, you will fight Hades.
Hades has 55535HP, and can be a pretty difficult boss -- unless you have already defeated Ozma. If you defeat Ozma first, then you'll get to see one of the most amusing battle dialogues in all of FF history :) If you defeat Hades, then he will open his synthesis shop and allow you to obtain some of the most powerful items in the game. The items Hades will synthesize are listed below.