Stormcaller Rune (IV)

+50% Lightning Damage.

Each Lightning Storm strike deals splash damage.

Each Lightning Storm strike creates a Lightning Ball that deals periodic Lightning damage in a small radius.

Each cleared boss encounter of level 40 and higher has a 2% chance to drop a rune (1.5% on mini-boss stages). On Inferno 0.5% of those runes are Set Runes before the stage's loot bonus and Item Find, which raise it; on Normal and Nightmare no Set Rune drops. Only runes for the current hero's class drop.