Electrocute

Hitting a champion with 3 separate attacks or abilities within 3s deals bonus adaptive damage. Damage: 70 - 240 (+0.1 bonus AD, +0.05 AP) damage. Cooldown: 20s 'We called them the Thunderlords, for to speak of their lightning was to invite disaster.'

Tree

Domination

Row

Keystone

In short

Hitting a champion with 3 separate attacks or abilities in 3s deals bonus adaptive damage.

Patch

16.16.1