Bitter Cold (3.5e Feat)
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Bitter Cold [Frost Knight]
Your abilities are so cold that they affect even creatures normally immune to cold damage.
Benefit: Any frost knight ability you use that deals cold damage deals one-half damage to creatures that are normally immune to cold (such as a night hag) any creature that possesses the cold subtype (a white dragon, for instance) is still immune to the cold damage. Cold resistance still applies normally.