Complete the following tasks to unlock the corresponding characters. Characters are switched by going to the top-left of the lobby in the Hero building. Note: Guy is unlocked by default.
Reach Floor 15 on Chaos mode with the 'Fresh Blood' Runeword.
Reach Floor 15 on Chaos mode with the 'Spell Breaker' Runeword.
Reach Floor 15 on Nightmare mode.
Reach Level 10 with 'Endless' Runewords.
Reach Floor 10 on Nightmare mode.
When the following conditins are met the corresponding upgrades can be purchased at the Upgrades Shop.
Maximize 1 upgrade
Maximize 3 upgrades
Maximize 7 upgrades
Maximize 4 upgrades
Maximize 2 upgrades
Maximize 5 upgrades
Maximize 6 upgrades
Maximize 9 upgrades
Maximize 8 upgrades.