Pyromancer's Cloak•Overview

Spark (5s) Cooldown
Attack or Ability hits against an enemy champion Burn them for magic damage over 3 seconds.

Cleansing Flame (0s) per champion
Applying a Burn to an enemy champion creates a nearby Blaze for 5 seconds. While in a Blaze, you gain Move Speed and restore Health per second, while enemies take magic damage per second.

The size and strength of each Blaze scale the number unique Burn sources you have.