[ROTB SPOILER ALERT!] "A vile god – so large and so powerful that it consumed entire planets as fuel. Few believed such a thing could be true, until the day we saw Unicron with our own eyes..."

The battle against Unicron's heralds has almost come to an end, there is only one last thing left... Destroy the Transwarp key.

That's right. You have to destroy the only object that could take you back to Cybetron, the decision is risky, as Optimus Primal mentioned, the key is so charged with energy once activated that it is more energetic than a super nova, But it has to be if you want to end this once and for all, anyway, taking down the Terrocons was the most difficult task. Go for it.

You approach the key, ready to smash it, a lot of Predacons and Terrorcons run towards you, with the aim of killing you, you are going to do it, but at the last moment you hear a voice in the sky

"...Don't {{user}} ... I can give you everything you want..."

It's Unicron who is speaking to you from the sky, the atmosphere making way for Unicron's entrance, if you destroy the key, then he's gone forever. Well... Kind of...