Frost Curse

| Frost % | Effect |
0–19%    Minor ice leaks; cosmetic only.
20–39%  Skin pale, breath mists. Disadvantage on checks to resist cold.
40–59%  Movement becomes sluggish. -5 ft speed.
60–79%  Vulnerability to Cold damage.
80–99%  Casting spells also causes 1d4 Cold damage to self.
100%       The caster freezes solid and is encased in magical ice.

Initial CON Save DC: 10 + Spell Level.
DC Increase: Add +1 for every 10% Frost.