To get the Magician Of Black Chaos, you must have a Dark Magician. The easy way to make him evolve is get him to level 3. Then, stop using him. When you reach area 5 and face Kaiba, you should use the Dark Magician. Have him almost to level 4 like 15 exp. to go. Know when he summons the Blue Eyes White Dragon and find a monster to weaken it so you can use your Dark Magician. When he kills the Blue Eyes, he will be level 4. Make sure nobody can kill him. You must wait until the field turns from light to dark. Then when you are on the dark ship, go to Your Dark
Magician. He should have evolve. Select it to get a Magician Of Black Chaos.