Jetpower Optimus Prime

Jet Optimus is the Optimus that combines with Jetfire in order to destroy The Fallen.

Fiction
As Jetfire dies because of Skorponok, before he shuts down, he gives his spark to Optimus to destroy The Fallen. As Jet Optimus then meets The Fallen, Megatron and Starscream, The Fallen is taken down while the other two flee as a result Jet Optimus would finish them off too.