Champion Rimewalker

Avalanche. For every attack that the Rimewalker succeeds on hitting during their turn they receive an Avalanche stack. Their AC is increased by +1 and receive a +1 Bonus to their Saving Throws, per Avalanche stack, until the start of their next turn.

Snowball Effect. In order to use their stronger attacks the Rimewalker must succeed in hitting it's previous attack. To use Rime, they must have hit their target with Frostbite. To use Glacial Smash, they must have hit their target with Rime.

Recursive Snowball. Hitting with Glacial Smash causes you to be at disadvantage on all attack rolls for the rest of this turn, but allows you to use Frostbite again on the target, allowing for infinite attacks. Each additional time Glacial Smash is used you receive a -8 to your chance to hit.

Frozen Core. Resistance to Cold damage. Vulnerability to Fire damage.

Frostbite. Melee Spell Attack: +9 to hit, reach 5 ft., 1 target. Hit: 14 (1d10 + 9) Cold damage.

Rime. Melee Spell Attack: +7 to hit, range 5 ft., 1 target. Hit: 17 (2d8 + 9) Cold damage.

Glacial Smash. Melee Spell Attack: +5 to hit, range 5 ft., 1 target. Hit: 21 (4d6 + 9) Cold damage.

Endless Winter . Volunteer to convert your defence into healing. Receive 1d10 + 3 healing per Avalanche stack currently affecting you. After this, lose all Avalanche stacks.

Ice Shield. AC increased by 5 and all magic missiles automatically miss, but you have disadvantage on your next Frostbite until the end of your next turn.