Each tick of Searing Blaze & Engulfing Flames has a 4% chance to have +100% critical strike chance.
The chance for Spontaneous Combustion to trigger is increased by +1% for every 5% critical strike chance you have.
GRIEVOUS CRITICAL STRIKE
Any critical strike chance you have beyond 100% causes a grievous critical strike. Grievous critical strikes increase the base damage of the hit by an amount equal to the overflowing critical strike chance.
Ardeos