Auril's Aegis

Upon using a shield bash (Requires shield master feat) the target must succeed a DC (equal to wielder's level) constitution saving throw or be 'petrified' (frozen) and receive 1D6 cold damage. At the end of each turn, the petrified target may make a save to shrug the effect. If they fail, they take an additional 1D6 cold damage.

As a bonus action the wielder may also strike the Aegis with their weapon. Augmenting it with 1D4 cold damage. (Duration: turns = player level)

Armour class bonus scales with player level:

1. Level1-4: +1
2. Level 5-9: +2
3. Level 10-14: +3
4. Level 15-20: +4

This shield also provides a resistance to fire damage from AOE. The shield also gives immunity to heated environments. 

Shields require the Utilize action to Don or Doff. You gain the Armor Class benefit of a Shield only if you have training with it.

Notes: The wielder must also swear celibacy, and sacrifice their first born child to the lady of Frost.