Rumble

Strengths

Try and pace yourself to stay in the Danger Zone to maximize your effectiveness. It is easy to overheat if you rapidly use your abilities.
Try and keep targets in the range of your Flamespitter. It can deal a lot of damage overtime.
If you are winning a fight you can use your ultimate to wall off an escape path.

Passive · Junkyard Titan — 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.
Q · 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.
W · 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.
E · 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.
Ultimate · The Equalizer — Rumble fires off a group of rockets, creating a wall of flames that damages and slows enemies.

A suggested 5-lane lineup built around Rumble, based on hero partnerships and role synergy — not win rate.