Complete the indicated Chapter in Adventure mode to unlock the corresponding character in the other modes.

Character	How to unlock
Draco Centauros	Clear Chapter 5.
Ecolo	Clear Chapter 7.
Feli	Clear Chapter 4.
Lemres	Clear Chapter 6.
Satan	Clear Chapter 6.
Schezo	Clear Chapter 4.
Witch	Clear Chapter 5.
X	Clear Chapter 7.