Icy Reflection: Once per long rest, when you are targeted by a spell or attack, you can use your reaction to summon a reflective icy barrier. Roll 1d6:

On a 4-6, the attack is reflected back to the attacker, dealing cold damage equal to the damage they would have dealt or forcing them to save against their own spell DC (if applicable).

On a 1-3, the ice barrier absorbs half the damage and shatters harmlessly.

Frost's veil: While holding this chalice, your cold damage spells or effects ignore resistance to cold damage.