Rumble's abilities don't have any cost related to them, so the use of his abilities is only limited by cooldowns. Instead, he uses heat as his secondary bar. Rumble starts with 0 heat, and it caps at 100.
Rumble's basic abilities generate 20 heat when used. When Rumble reaches 50 heat, he is in the Danger Zone, causing all his basic skills to have enhanced effects. When Rumble reaches 100 heat he overheats, silencing himself for 6 seconds after which he will cooldown completely, during this time all his basic attacks deal additional magic damage. While not overheated, after 4 seconds of not using his basic abilities he will start losing heat at a rate of 5 heat every half second, and 2.5 seconds later at a rate of 10 every half second.
When Rumble reaches 100 heat he overheats, silencing himself for 6 seconds to cooldown completely and causing his basic attacks to deal an additional 20 + (5 x level) + (0.3 per ability power) magic damage for the duration.
Active: Rumble shoots a taser that deals magic damage and applies a slow on the first enemy it hit for 3 seconds. A second shot can be fired for no additional cost within the next three seconds, even if Rumble overheats. If the second taser slows an enemy that has been slowed by the first, the slow is refreshed and its movement speed reduction is doubled.
Active: Rumble calls down a line of rockets over the target linear location, using a click and drag targeting system. The rockets deal initial magic damage to all enemies hit on arrival, and also leave a trail of destruction for 5 seconds that slows by 35% and deals magic damage every second to all enemies standing on the area.
Initial Magic Damage： 150 / 225 / 300 (+ 50% AP)
Area Magic Damage Per Second： 100 / 140 / 180 (+ 20% AP)