Every spell Rumble casts gives him Heat. When he reaches 50% Heat he reaches Danger Zone, granting all his basic abilities bonus effects. When he reaches 100% Heat, he starts Overheating, gaining bonus Attack Speed and granting his basic attacks bonus damage, but making him unable to cast spells for a few seconds.
Flamespitter
Rumble torches opponents in front of him, dealing magic damage in a cone for 3 seconds. While in Danger Zone this damage is increased.
Scrap Shield
Rumble pulls up a shield, protecting him from damage and granting him a quick burst of speed. While in Danger Zone, the shield strength and speed bonus is increased.
Electro Harpoon
Rumble launches a harpoon, electrocuting his target with magic damage, slowing their Move Speed, and reducing their Magic Resist. Rumble can carry 2 harpoons at a time. While in Danger Zone the damage and slow percentage is increased.
The Equalizer
Rumble fires off a group of rockets, creating a wall of flames that damages and slows enemies.