Vengeful Dwarven Warhammer

Damage: 1d8 (V:1d10) Bludgeoning + 1d4 Force
Modifiers: Melee Attacks +1, Melee Damage +2
When you roll a 20 on your attack roll with this
Magic Weapon, the target takes an extra 2d8
bludgeoning damage.
This extra damage increases by 2d8 for every
additional 20 you roll on your attack roll, stacking
until the next day at dawn, when it resets.
Requires Attunement.