F-Grade Spark? He Became The Thunder God

Kaelen, a Black Dragon prodigy, awakened at 18 with only a weak "Spark". Branded a bloodline mongrel, he was stripped of resources, dragon bone torn out, exiled, publicly divorced by his proud Red Dragon fiancée. Dying, he unlocked the Thunder Proficiency Evolution System: every lightning skill permanently doubles proficiency, damage and range stacking forever. Ten thousand snaps turned a spark into a god-rending thunderstorm. With countless bolts he returns to settle scores with Dragon Kings.