Quick recap
Blackarachnia activates the Ark's defenses and drives Megatron off. To save Optimus Prime, Optimus Primal holds his spark inside his own body and becomes the giant Optimal Optimus; then he returns the spark, and the Maximals exist again. The Ark becomes their base. Megatron creates Dinobot II, a clone of Dinobot; Cheetor turns into a feral Transmetal II before regaining control; and Blackarachnia accepts that she's a Maximal. Tigerhawk, a fusion of Tigatron and Airazor, joins the team. In the end, Megatron takes over the Nemesis, the original Decepticons' warship. Tigerhawk, Inferno and Quickstrike die, Dinobot II distracts Megatron, and Rhinox crashes a shuttle through the Nemesis bridge. The Maximals head home to Cybertron with Megatron in restraints, and Waspinator is left as leader of humanity's ancestors.