Grand Theft Auto : Thundera
GTA belongs to Rockstar games; Thundercats belongs to Rankin Bass/Warner Bros.
All GTA characters are at the same age as in the games.
Prologue
Black Pyramid, Third Earth, 8005 A.D.
Mumm-Ra was inside the Pyramid, discussing with the Ancient Spirits of Evil about his plans. Before that, he had obtained the four Power Stones and the Book of Omens. Now, Mumm-Ra is planning on a bigger scheme.
"Ancient Spirits of Evil! I've successfully obtained all the Power Stones and the Book of Omens! Now, what must I do to rule over the Universe?" commanded Mumm-Ra.
"You must now summon a portal, return to your past and aid your past self to rule over the Universe. The portal will bring you back 6000 years in the past. But, you will face three humans who will fight against you. Remember, failure will cause your banishment from the mortal realm." said the Ancient Spirits of Evil.
Pumyra, who once betrayed Lion-O, overheard him. She was conscience stricken, as she realized that he will change the course of history forever. She quickly escapes to warn the Thundercats about his next plan.
The Thundercats were just outside the Black Pyramid, discussing on what to do in order to reclaim the Power Stones and the Book of Omens. Lion-O heard footsteps approaching, thinking it was a recon sent by Mumm-Ra, informed the rest of the team that they are spotted. But when the figure shows up, Lion-O realizes it was Pumyra. Lion-O thought she was going to kill him, but he was wrong. Pumyra said "Lion-O, I'm sorry. I shouldn't have betrayed you. But listen, Mumm-Ra is now going to return to the past, helping his past self to rule over the Universe. This will change the course of history, we must stop him!"
Lion-O was glad that she wasn't meant to kill him, but the rest of the team were skeptical. "Lion-O, how we could tell she wasn't lying?" asked Tygra, who still remember his experience of being betrayed.
"The only important thing is that she repented, and that's what matters." Replied Lion-O. "We must stop Mumm-Ra's plans."
So the Thundercats entered the Pyramid, hoping it isn't too late to stop him. But by the time they arrived, Mumm-Ra was delighted to see them. "Ah, you're just in time, to witness your end! I'm going to return to the past to aid my past self to rule over the Universe, this time none shall survive!" said Mumm-Ra.
The portal was created using the Book of Omens and the four Power Stones, and Mumm-Ra, along with the Mutants and the Lunataks entered the portal. "Quick, enter the portal! We must stop them!" commanded Lion-O.
But, the portal was unstable; it was getting bigger, sucking more things in, and eventually sucking the Thundercats, the Black Pyramid and the entire Third Earth in.
Somewhere in the West Coast, United States, First Earth, January 1 2015.
The barren shore side of the West Coast was a no man's land, with only a gas station, a motel and a diner. Some college students were sleeping at the porch outside of the motel. "Man, this place stinks, I'll sell my soul for excitement" said a college student.
Suddenly, a huge land mass appears over the sea several thousand kilometers away, complete with forests, deserts, canyons ,hills and beaches. "Mother of God, what just happened!" said the college student. Quickly, they scram and ran away, never to be seen.
The Thundercats showed up, but they found out that the portal brought along everyone on Third Earth. Lion-O was shocked to see all of Third Earth was brought along, but he stayed calm and said "Let's build a civilization in this strange land, while we hunt for them."
Meanwhile, Mumm-Ra, the Mutants and the Lunataks showed up somewhere in the middle of the Pacific Ocean. "What on Third Earth is this place?" exclaimed Mumm-Ra. Chilla replied "Our information states that we are at what First Earthers call the Pacific Ocean.". "Damn it, now we have to swim our way to the shore." said Kaynar.
"Apparently there's a cargo ship in front of us." said Vultaire. "What are you pricks waiting for? Swim there and take it!" commanded Mumm-Ra. So the Mutants, the Lunataks and Mumm-Ra swam forward to the ship.
"Wait, where are the Power Stones and the Book of Omens? No!" exclaimed Mumm-Ra, realizing that they have lost both the Power Stones and the Book of Omens.