In the aftermath of their first battle against the Unicron Flayer, almost everyone on Cybertron got word of Unicron's return, and boy, were they shocked. 

Maestra: "Our lord has returned!"

Blackfire: "It is a miracle!"

Nightmare: "You Auto-brats are finally screwed now!"

Meanwhile, the A.N.D. Global Command also got the bad news about Unicron. 

ArmoRiot: "Is that supposed to be Unicron?"

Black Star: "He's looking worse."

AlcheMina: "Major Worse."

Vibe: "Like, Ultra-worse."

Then, news of the Unicron Flayer spread throughout the Universe. 

Back on Earth, the Autobot-Human Alliance was met with old friends, and they couldn't be happier, but some of them aren't happy. 

Optimus: "I'm afraid it's worse; Unicron is still alive."

Finn: "Yeah, he's become the "Unicron Flayer"."

Kup: "This can't be!"

Percy: "Unicron Flayer?"

Not when Alice reveals that she was the one who made Vecna into what he is now, because if it wasn't for her sending 001/Henry Creel into the Upside-Down, Dio wouldn't be taken by the Demogorgon, or possessed by the Mind Flayer, and none of those people had to be sacrificed for Vecna. 

Alice: "Back when we were on Cybertron, Vecna told me, I was the one who made him into a monster, not only that, he was behind everything, Dio's disappearance, the Mind Flayer, all their sacrifices, it all began with me. I... am the cause of all this!"

Finn: "You looked into my Visions?"

It feels like the past sins of 1979 have finally caught up to her. 

Rikka: "So what? You're still Alice. And besides it's thanks to you and Primus that everyone's okay."

Zoe: "So what's there to worry-"

Alice: "NOTHING'S OKAY!!! NOTHING! If I hadn't sent Vecna to the Upside-Down, Dio wouldn't have been taken, the Mind Flayer wouldn't have possessed him, Rikka wouldn't have lost Brody, and Vecna wouldn't have started his rampage! Everything that's happened to us, to Hawkins, it's all my fault!"

Then, Alice runs away, not wanting to involve her friends any further. At this point, all hope is lost for both Earth and Humanity. 

Marco: "So, all is lost, after all?"

???: "Not exactly. Who needs a princess, when you have me?"

But, who is that handsome man who assures our young heroes that everything will be fine?

Meanwhile, on Cybertron, the Elite Guard and the Autobots Next Door are discussing how to deal with the Unicron Flayer. 

Captain AirRaptor: "We must plan an attack from inside Unicron."

Blazer: "But, how? 

[...]

Rainbolt: "We must stop Unicron somehow."

Then, the Quintessons called and came to a decision: if the Unicron Flayer were to take over Earth as his new body, Earth must be destroyed. 

Rainbolt: "Destroy Earth?"

Glowpack: "Are they nuts?!"

Black Star: "They can't do that!"

This shocks everyone in the Elite Guard and the Autobots Next Door, but not the remnants of the once-powerful Unicron Alliance, as they seem to be okay with it. 

Nightmare: "That means your precious Earth friends will be dead!"

Dragochain: "You do realize that if the Earth goes, Unicron goes too?"

Meanwhile, on Planet Q, Queen Quintessa laments making this decision but, Alpha Q sees no problem in ending Unicron's reign, at all costs. 

Quintessa: "This is a terrible idea."

Alpha Q(Face of Kindness): "If we don't stop Unicron, Earth will become his new body."

Alpha Q(Face of Truth): "Then, this is our only option."

Back on Earth, Sector Seven's Agent Simmons has his team use the Satellite Cannon to bring an end to the Unicron Flayer for good. 

Simmons: "Our Satellite Cannon has enough power to destroy the Unicron Flayer for good."

The cannon targets the giant Gate and it fires a powerful laser that seemingly destroys Unicron, or so they thought. 

[Satellite Cannon fires]

Vecna: "Oh sh-"

Simmons: "Direct hit!"

Vecna appears in said satellite and kills everyone before destroying the Satellite Cannon and sending it crashing down into the gate. 

Vecna: "Big mistake."

At this point, Unicron is really pissed off. Now, the Party has no choice but to find Alice and bring her back. If she ever wants to come back.

Finn: "We need to get Alice back."