Vincent

Vincent is an optional character that can be found in the Shinra Mansion basement. To reach him you'l need to first obtain the combination to a safe on the top floor. The clues to find this combination are found in a book on the main floor in the room to the left. The first clue is in the box in the atrium. The second clue is on the floor near the piano. The third clue is scratched on the squeaky floor in the upstairs hallway. The last number is simply written in the last spot in the book in invisible ink. The combination you get should be Right 36, Left 10, Right 59, Right 97. The safe that this combination opens is found on the top floor in the upper left room. When you examine the safe you have the option to enter the combination. You'll have 30 seconds to enter the combination. Spin the dial being careful not to go past the combo number. When you hit each number push the X button.

When you successfully input the combination the Odin materia pops out but you're immediately sent into battle with the boss Lost Number.

Level: 35, HP: 1000, MP: 100, EXP: 2000, Gil: 2000, AP: 80

Lost Number is invulnerable to gravity magic so Demi will do nothing to it. It uses multiple elemental attacks including Bolt, Fire, and Quake. However, Bolt does work well against it. The key to this battle is to use ChocoMog. It's vulnerable to Stop but it may take a few attacks to stop it.

After this battle you'll get the key to the basement (don't forget to pick up the Odin materia). Go into the basement and open the door in the hallway. Open the closed coffin and speak to Vincent. Tell him about Sephiroth. He'll talk for awhile and then go back to sleep. Wake him up and find out his name. He'll go back to sleep again. Go to leave and he'll join your party.

Lucrecia's Cave

Once you have a Gold Chocobo or the submarine you can get more of Vincent's story. Lucrecia's cave is behind a waterfall in a lagoon near Nibel. With the submarine you'll have to navigate through a cave east of the lagoon. Park your sub or chocobo on a ledge to the left of the cave.

When you visit on Disc 2 you'll meet Lucrecia and learn more about Vincent.

Visit again during Disc 3 to get Vincent's ultimate weapon Death Penalty and his Chaos Limit Break.