Metrobomb ->
Metrobomb -> Bomb-Burst
Metrobomb -> Bomb-Burst -> Starscream
(Had to go the obvious )
Metrobomb -> Bomb-Burst -> Starscream -> Megadeath
Metrobomb -> Bomb-Burst -> Starscream -> Megadeath -> The Fallen
Metrobomb -> Bomb-Burst -> Starscream -> Megadeath -> The Fallen -> Nautilator