Bension is an "okay" ability, but could be done better given that is has a cooldown (even if it's short), and relies on the Lily system (which is another gate to use it).

I would suggest either of the following changes

Scenario A)
- Mitigation at 15%
- Only consumes 1 Lily regardless of how many the player has

Scenario B)
- Mitigation scales with # of Lilies
1 Lily = 15% shield
2 Lilies = 18% shield (old Stoneskin value)
3 Lilies = 20% shield
- Consumes all Lilies