Cleave

Cleave is a Primary skill.

In-game
Each attack slashes a degrees arc in front of the Barbarian, roughly  yards long, effectively hitting a broad cone.

This skill is a fast hit, but has a slight delay between uses, making it slightly slower than normal attacks. It can be delivered with one hand, and seems to alternate between forehand and backhand, so it can be used while the Barbarian is Dual-Wielding.

Runes

 * Rupture: Damage type changes to Fire, and enemies slain by Cleave explode for damage as Fire to enemies within  yards.
 * Reaping Swing: Damage type changes to Fire, and generates Fury for each enemy hit.
 * Scattering Blast: An enemy critically hit, but not killed with Cleave is also knocked up briefly, and upon landing, enemies within yards (including the target knocked up) suffer  damage as Physical. If an enemy is immune to Knockback, they suffer extra damage immediately.
 * Broad Sweep: The Barbarian now swings to hit enemies within  yards of themselves. In addition, the damage type changes to Lightning, and all damage dealt is increased to.
 * Gathering Storm: Cleave now deals Cold damage, and all enemies hit by the Cleave are also Chilled by, and suffer more damage for  seconds. These effects do not stack.

Non-rune enhancements

 * Depth Diggers (Legendary Pants): damage increases by 80-100%.
 * Oathkeeper (Legendary Mighty Weapon): attacks 50% faster and deals 150-200% increased damage.
 * Dishonored Legacy (Legendary Mighty Weapon): increases damage by up to 300-400%, proportionally to the percentage of missing Fury (more damage when low on Fury).
 * Simplicity's Strength (Legendary Gem): increases damage by 25% (+0.5% per rank) and heals the character for 4% of maximum Life per hit (rank 25 bonus).
 * Boyarsky's Chip (Legendary Gem): Taunts the first enemy hit for 2 seconds (rank 25 bonus).
 * Vambraces of Sescheron (Legendary Bracers): each damaging cast heals the Barbarian for 5-6% of missing (not maximum) Life.