League of Legends Reforged Rune: Conqueror

Basic attacks on-damage against enemy champions grant (2 for Melee / 1 for Ranged) stacks of Conqueror. Abilities, spells and item actives on-damage will grant 2 stacks.

Each stack of Conqueror grants 1.2−2.7 bonus Attack Damage (depending on level) or 2−4.5 Ability Power (depending on level) for 5 seconds (Adaptive), stacking up to 12 times, for a maximum of 14.4−32.4 bonus Attack Damage (depending on level) or 24−54 Ability Power (depending on level). While fully stacked, you heal for (9% for Melee / 6% Ranged) of the post-mitigation damage from any attack you deal to enemy champions, and the stacks refresh upon dealing damage to enemy champions with attacks or abilities.

Persistent damage and ongoing sources of damage will grant the stacks only once every 5 seconds. Spells and effects that deal default damage will not grant any stacks.