Viking

Storm, Earth, and Fire
Beginning at 8th level, whenever you damage an enemy with a weapon attack, or an enemy damages you with a weapon attack, the enemy is afflicted with one stack of Fury. No creature may ever be afflicted with more stacks of Fury than it has Hit Dice. As a bonus action, you may invoke your fury on a target, consuming all stacks of Fury on that creature and causing your next successful Weapon attack against it before the end of the current turn to deal 1d6 additional damage for every stack consumed. This damage is either Bludgeoning, Fire, or Lightning, chosen by you when you invoke your fury. Fury dissipates if no stacks are gained for one minute.

Blood Tide
Beginning at 13th level, when you make a weapon attack benefiting from Tension, your critical range is increased by 1, or by 2 if you are attacking with SUPER HIGH TENSION. Additionally, when you score a critical hit, every enemy within 60' is afflicted with one stack of Fury, and then takes 1d6 damage for every stack of Fury afflicting them. This damage is either Bludgeoning, Fire, or Lightning, chosen by you when you invoke your fury. This effect does not consume stacks of Fury.

Appetite for Destruction
Beginning at 18th level, whenever an enemy within 60' is reduced to 0 HP, you may afflict up to two other creatures within 60' with a number of stacks of Fury equal to those remaining on the defeated creature. If the creature was reduced to 0 HP by an attack augmented by your Storm, Earth, and Fire ability, you may instead afflict two other creatures within 60' with a number of stacks of Fury consumed by that attack.