I'm still level 1 and I never did anything special, so default 60 points used to remove the old signature and replace it with a new one.
Signature Attack:
Valor Beam (Normal Element)
Effect: Seeking, deals 40 Damage
Cost: 60 Pts
Turn Cooldown rate: 2 Turns
The Validus Cannon loads up an alternative firing mode, and instead of firing in one cannon-like shot, it launches a beam that finds it's mark even on foes who have rendered themselves invisible.