Shokaract returns to Earth's past to secure his future.
Shokaract begins to live up to his name. As he and the Beasties battle, the Covenanti arrive from the future and assault him as well. Megatron, though, guesses correctly at Shokaract's intentions, and he slinks into the cave to fire upon the Dark Essence. It seems that Unicron is in constant danger of being pulled back to 2005, and the threat posed by Megatron's onslaught is critical. So Shokaract uses the future Dark Essence that he carries with him to cement the past Dark Essence's hold in space-time.
Meanwhile, temporal reality begins to break apart: Beast Warriors from alternate timelines (like Polar Claw and Torca) are pulled into the melee. Plus several G1 figures (such as Optimus Prime and Megatron) also arrive from the future, having reconsidered their J'nwan solitude. Even Apelinq, who had silently observed the Beast Wars for quite some time, pitches in at last. As Shokaract fends off these new combatants, he somehow resurrects the mind-wiped Antagony and atomized Cataclysm. However, the Covenanti turn themselves into energy beings and enter his Matrix of Conquest, where they merge into a Primus-like being, fight Unicron's Essence and sever the bond that's holding the past Essence in place.
As the past Essence is pulled to its final destiny, history begins to rewrite itself. Transwarp portals open for all the displaced combatants, and as they retreat to their own times and places, Shokaract explodes mightily.
And finally, we see the Hunter, on his way to the cave where his dark destiny awaits, but what he discovers is nothing at all.
(Numbers indicate order of appearance.)