rumble is a melee AP caster champion, he is durable in battle and has a great crowd control, rumble uses heat so you don't have to think about wasting mana in using his abilities. focusing his movement, durability and empowering his abilities gives him a huge advantage in large team fights. AP dominance focuses on how to make him durable and gives him a huge damage on his abilities. enjoy =))

buying an amplifying tome gives him a lot of mana in early game so that you can harass in the lane, then completely rushing into rylai's crystal scepter and a sorcerer's shoes for for ability power and magic penatration. after that buy shurelia's reverie for cooldown reduction and health. the buy force of nature for magic resistance, rabbadon's deathcap and zhonya's hourglass for armor and ability power.

max out flamespitter for early laning dominance, then max out electro harpoon for slow and max scrap sheild last. get the equalizer every time its available