[@Error] [color=lightgray][i]Couldnt it then be 21. Would give him a last chance type thing. THAT should have been the ablity[/i][/color]

Something like: 'Skill: Cost [color=fff200]X[/color]. When Master's health hits zero he may recover X/10 health' or something similar?

I say X/10, since at full power that'd still only give you 10 health back. Getting 100 health might be a little excessive. Alternatively it could be 'X% Health' since that would then scale up nicely as you level up, but would make the power weaker early on.