Democratic Monster Creation or something

[Mr_GrinReaper]

Sounds like the DC would be above 20 X_X, so.... yea, that would work, it would read as-

Negative Energy Taint- Any attempt to cast a spell using positive energy must succeed on a DC XX Caster level check, if within 60 feet of the _______, or the positive energy becomes negative energy, and heals undead, but hurts the living, a caster may voluntarily fail the check in order to use this offensively.

 

[Macrovore]

This sounds like at least CR 16
A challenging adversary for my group
*smiles cruelly and presses fingertips together as eyes begin to glow red*

*-Insert best villianous laugh (or is it more of a cackle?) concieved by man here-*