To unlock the following Archers, complete the following tasks.

Unlockable	How to unlock
Ancient Exile (white)	Unlock and play the Moonstage level and break the purple crystal that contains Ancient Exile.
Forgotten Master (yellow)	Collect all seven yellow gems hidden throughout the levels in Trial mode.
Prancing Puppet (cyan)	Unlock the Sunken City level.
Vicious Vessel (purple)	Play Versus mode on the Twilight Spire level until a random event occurs.