Stats

Armor, magic resist, mana and attack speed are the same at every star level.

Rumble

1 star: For 3 seconds, gain 0.35 Durability and create a cone of flame that deals 220 magic damage over the duration and Wounds enemies for 5 seconds. Wound: Reduce healing received by 33%
2 star: For 3 seconds, gain 0.35 Durability and create a cone of flame that deals 330 magic damage over the duration and Wounds enemies for 5 seconds. Wound: Reduce healing received by 33%
3 star: For 3 seconds, gain 0.35 Durability and create a cone of flame that deals 495 magic damage over the duration and Wounds enemies for 5 seconds. Wound: Reduce healing received by 33%

3 patches changed Rumble, read out of Riot’s game files.