Once inside the core, Dark Gaia releases a shockwave that spreads across the globe, unleashing eternal darkness. Dark Gaia then undergoes a transformation to his mature state; Perfect Dark Gaia.
Perfect Dark Gaia looks down at the Demon Shredder who seemed like little more than a speck of dust to him.
The Demon Shredder growls as he blasts a very powerful surge of dark magic at Dark Gaia, only to regret it as Dark Gaia absorbs the blast and becomes even more powerful!
Perfect Dark Gaia stands even taller as it roars, much to the Shredder's shock. Perfect Dark Gaia then summons his Gaia Canon again, only this time it's even stronger and could easily pierce through planets. Dark Gaia blasts the Gaia Canon at Shredder, who quickly teleports out of the way as the Gaia Canon goes right out of the Core and into space. Demon Shredder flies at Dark Gaia at supersonic speeds, only to be swatted away like an insect, as he flies backwards crashing against the walls of the core and landing on a floating rock platform.
An enraged Demon Shredder flies back up and uses his TK to lift all of the giant floating rock platforms as he throws them at Dark Gaia. Dark Gaia protects himself with an invisible shield composed of dark energy. Shredder lifts a mountain using TK and throws it at Dark Gaia. Dark Gaia's shield once again proved to powerful as the mountain shatters upon impact with no result.
Shredder grows into a giant, approaches Dark Gaia, and punches away at Dark Gaia, only to be blocked by the invisible shield. He could amp his fists with dark magic, but that would only feed Dark Gaia. Dark Gaia uses all six of his arms to attack the Shredder, but as he focused on moving his arms, his focus on his shield was broken as Shredder manages to land power blows at great speed. He kept punching, punching, and kicking but his blows had little to no effect. Dark Gaia TRIED to fight back, but his lack of speed and skill is preventing him from throwing a punch back, even if Shredder's blows weren't doing much. At one point however, Gaia had managed to grab the Shredder's arms, tear them clean off, and blast the Shredder away with his Gaia Canon which sends him flying backwards and crashing into a mountain. The Gaia Canon had pierced right through Shredder's chest. Shredder stands back up, shrinks to normal size, and growls as he refocuses all of his power. From across the globe, all of the Shredder's dark magic returns to him, as he then transforms into his Dragon form. He roars as he glows with immense energy, floating in mid-air.
Dark Gaia roars as well as he summons his perfect shield, which was visible and it covered a huge distance. Shredder stands on top of a giant floating rock platform as he blasts away an energy beam which contained the attack potency of a planet buster at Gaia's shield. Dark Gaia struggles trying to keep the shield up. After a while, the shield goes down, as the Shredder flies at Dark Gaia. The two beasts roaring as they go all out. Dark Gaia throws a power punch, but Shredder uses his skill and speed to fly and maneuver around it as he punches Dark Gaia in his face, nearly knocking him over. Dark Gaia uses it's tentacles to try to grab Shredder but he blasts them away. Dark Gaia tries to swat Shredder again, but he quickly flies around it, lands on one of Gaia's arm, and blasts away mystical fire at Dark Gaia's eyes, burning a few of them. Dark Gaia quickly flicks Shredder away before holding his eyes in pain, roaring. The flick had sent Shredder flying back, but he stops in mid-air.
Dark Gaia decides to grow in size-up to his continent sized form! He busts right out of the core and roars as he looks down, trying to spot Shredder. He was so huge that Shredder seemed like a germ to him, no, even smaller! He then looks down at the core, and tries to grasp Shredder. Unfortunately for Dark Gaia however-though he may seem big in this form, his power wasn't condensed, therefore he was actually a lot weaker and slower in his continent sized form. He tries to grasp Shredder, only to have Shredder rapidly punch and blast his way through. Dark Gaia roars in frustration.
Shredder quickly charges up his energy blast, as he blasts Dark Gaia's hand with the attack potency of a planet buster as Dark Gaia roars in pain. Dark Gaia then growls before shrinking back to the size it was before.
As Dark Gaia shakes off the pain, he summons a dark giant energy ball as he charges it up. It had enough power to blow the entire planet sky high as he throws it at Shredder. Shredder quickly blasts away everything he's got at the energy ball all at once. He sends energy blasts from his hands and his mouth at it, but this only slowed down the blast and made it slightly weaker as the power struggle continues.
And while all of this is happening, Shredder had been mind raping Dark Gaia, preventing him from fully tapping into his powers. If not for this, Dark Gaia would have thrown up to six of those giant energy balls, and since Shredder has to exceed himself just to stop one of them, it would have been the end of him along with the rest of the planet.
Shredder continues trying to hold back Dark Gaia's planet busting energy ball as the power struggle continues. Gaia's energy ball however, proved to be to strong as it slowly gets closer to the Shredder. When it reaches Shredder, Shredder gets a strong grip on it, trying to push it back... But, the energy ball was just too strong... It pushes Shredder back as Shredder seemed unable to stop it. He then fully taps into all of his powers, as his body glows with a red aura. He lets out a huge roar before he suddenly blasts the energy ball right back at Dark Gaia. The energy ball hits Dark Gaia causing a huge explosion. Dark Gaia is then stunned from the blast as he tries to move. This gave Shredder the opportunity to fly right at Dark Gaia and hit him with everything he had-he claws at him like there's no tomorrow, blasts him like crazy, and at one point he digs his amped claws right into Dark Gaia's main eye. As Dark Gaia regains control of himself, he quickly swats Shredder with all six of his arms, tearing him apart... The injured and defeated Dark Gaia however, was unable to fight any further as he collapses and sinks into the lava.
The pieces of the dragon Shredder falls onto a floating rock platform, as he slowly regenerates. The dragon Shredder then deforms to his regular form, as Shredder holds his head in exhaustion.
Shredder:Urgh...
So why did Shredder triumph over Dark Gaia? Mostly because of his haxxed abilities, of course. While Dark Gaia had the advantage in size and raw power, it was seriously lacking in speed, skill, and it lacked the abilities needed to counter Shredder's mind rape and reality warping-which is mainly what saved his ass from being nuked by Gaia spamming planet busting energy balls. His reality warping gives him the ability to increase his power with EVERY. PASSING. SECOND. He also prevented Gaia from fully tapping into his power by mind raping him, messing up Gaia's concentration and focus to high proportions. So while Shredder's power was growing by the second, Gaia's was decreasing for he was unable to fully tap into all of his powers, and since the two of them are almost equal in destructive capacity, this had a huge impact on the battle and it greatly turned the tide in Shredder's favor. And I could already hear the downplayers raging, "OH, but Shredder doesn't use mind rape in battle! that is out of character! Plus Shredder always toys with his enemies!" Actually, Shredder only toys with his enemies if he KNOWS he's stronger than them. When he's up against someone with equal or greater power, then he actually goes all out. This is made evident when he fights the Ninja Tribunal back in 300 AD-he was bloodlusted and he wasn't toying around with them because he KNEW they were just as strong as he was at that time. Why didn't Shredder mind rape the Ninja Tribunal? Because they also had the ability to mind rape, which can be seen when Khan uses his mind powers to erase the Turtles' memories in the episode, "Fathers and sons" when they were just children. Why didn't Shredder mind rape the Turtles? The Turtles have proven multiple times that they can resist mind rape very well-to the point that even trying to mind rape them is just a waste of time and effort. As for all the, "OH BUT DARK GAIA COULD HAVE EASILY CRUSHED SHREDDAH IN HIS CONTINENT SIZE FORM BECAUSE HE'S SO FREAKING HUGE! SD" Hahaha, NO. For three reasons;
One - Dark Gaia in his continent size form lacks power condensation, which explains why he looked all purplish and unstable in the opening. Dark Gaia is actually a lot stronger when he's smaller because his power is CONDENSED, and he's a whole lot faster too despite not being able to cover as much distance. If Gaia in his continent size form tried to grasp Shredder, then Shredder would have just punched and blast his way through. Size does NOT always equal greater power. Just look at Super Sonic.
Two - Shredder's mind raping would have most likely prevented him from growing, but I just did that to give you downplayers and haters the benefit of a doubt.
Three - Gaia can't even support his continent size form for more than a minute, so what's the fucking point? :/