The battle with Krang was in full swing when Metalhead & Donatello joined the others. Leonardo's attacks were bouncing off of Krang's armor as the tachyon energy instead off cutting into him was instead bouncing off of a barrier that surrounded Krang. Michelangelo had wrapped Krang's arms to his sides as best as he could, but he could not breach the barrier to really stop him. Krang on the other hand was just as limited as the turtles as he did not want to run the risk of destroying his equipment. He was already furious that his precious ooze had spilled in the fight between the turtle & the idiot human. He may have been the lead scientist engineering the mutagen that Krang needed, but he wasn't Krang's only source. Krang cursed his youth, he found a mutagen decades ago that granted him not only advanced psychic & psionic abilities, but he had also grown a full humanoid body to compensate for the enhanced abilities he gained. Like a fool he destroyed the planet & all traces of it so that no one else could ever achieve his greatness & under the guises of Ch'rell, Torrinon, Kako Naso & Duke Acureds Krang was responsible for the deaths of millions across the universe. But Mortu & his advanced war suit had completely destroyed the planet Palmadise in their battle. The battle exhausted all of Krang's advanced powers & Mortu had utilized more than 7 different war suits & even ended the battle with a mixed matched prototype he had created using the parts of all the different war suits. Even now Krang could sense him, he knew Mortu was close probably using the turtle exoskeleton to stand in unison with these blasted reptiles. The reptiles that as of now were more of a nuisance to him than anything. His suits molecular amplification unit had been enhanced with Triceriton technology allowed him to increase his strength in addition to his size but in his own laboratory he was limited. This worked out in the turtles' favor since even though they weren't able to damage Krang he was also not able to use he full artillery. Donatello knew they had to break the barrier before they could make any headway. With Krang increasing his size to stand nearly 12ft there was no way they could overpower him. Donatello pulled down his googles to get whatever information his scanners could present. The first thing that was identified was the impact absorption mechanism which can absorb the force of any blow limiting the damage that he & Michelangelo's blunt force weapons could produce. Krang's suit also had unrestricted joint movement allowing him to move his limbs freely, both horizontally & vertically. The unrestricted detach/attach mechanism lets Krang to detach the framework, leaving only elastic skin & titanium cables that can't be easily cut, making it hard for Leonardo to destroy. The anti-piercing armor was woven steel that surrounds the area where Krang sat at the controls of his exosuit to protect him from Raphael's piercing attacks. Mortu began firing his plasma cannon at the barrier trying to overload it, but the barrier was dispersing the energy on impact leaving Krang without damage. "Same time" yelled Leonardo as everyone attacked the barrier at the same time. The flash of light was blinding & when the turtles looked at Krang he was perfectly fine. The barrier had withstood everything, but this time Donatello & Mortu were able to scan the damage as it happened. "Our weapons as powered by different energy sources right" asked Donatello. Mortu nodded while continuing to fire at Krang. He knew he energy was rapidly depleting but he wasn't going to give up on this battle. He looked at everyone & told them to give their new weapons to Metalhead. Once he fires all of that energy point blank into the barrier it should break down. Each brother gave one of their handheld devices then stood at the ready. Over the headset April told them that she found a giant service tunnel that connects to the Technodrome which was stationed below the building. Leonardo looked at his brothers then called for a regroup. "If the barrier goes down we don't know how long we will have, so we need to be in position. Mikey, once the barrier is down bind his arms so Krang can't move. I'll cut off the head, if it doesn't stop it completely then at least we'll have access directly to Krang". Raphael smirked & took off running. "Dude, where are you going?" asked Michelangelo. Raphael smiled & said "I'm gonna find something that goes boom". Mortu loaded the handhelds into his exosuits core & Metalhead's eyes began to glow. The turtles took the lead attacking as hard as they could, even Raphael made it back with a couple of grenades attached to his belt buckle. As they fought the Metalhead exosuit raised up a single cannon. Inside red, blue, purple, white & orange swirled before the multi-colored beam crashed into Krang. Instantly the barrier buckled & cracked like glass. Without hesitation Michelangelo yelled as he wrapped the razor wire around Krang's body. Leonardo sprinted up one of the pillars & used his momentum to reach neck level with Krang suit. His slash cut halfway through the neck leaving a lot of damage but not enough room for Raphael's explosives. On cue Donatello activated the Gravity Gauntlet causing the hear piece to tilt backwards. Knowing his options were limited Krang used his enhanced strength to shrug off Michelangelo but that was a mistake. Once Michelangelo landed on the ground he ran behind Krang, wrapped the wire & began to pull on the head piece. Krang aimed his own plasma cannon at Michelangelo but was cut across the eye by Leonardo. The Metalhead exosuit stood rigid as the power was completely drained essentially trapping Mortu inside, but he didn't care. He could watch the actions of his allies until the backup power kicked in. Raphael charge at the suit & pulled the pin on one of the grenades. He threw it high but Krang was able to catch it. Raphael smiled & threw his sai at the base of the head finally forcing it to break off. Michelangelo spun on his heels & wrapped the wire around Krang's exo suits' right arm so it wouldn't move. Donatello focused a gravitational pull at the left arm forcing it to connect to the ground. April opened up the service tunnel like she said & the turtles saw that it was several feet to the left. Leonardo began to hack away at the exosuits legs planning to eliminate all mobility while Raphael climbed to the now open neck & dropped a grenade inside. The resulting explosion blew Krang backwards as the suit was no longer able to properly function. In desperation Krang ejected his mobile portion to escape but at that same time the Metalhead exosuit lit up. Faster than Krang thought possible Mortu grabbed him & lifted Krang above his head. Mortu began to rip the legs & blasters off of Krang's mobile suit then used the plasma laser to melt the top to the bottom locking Krang inside. As a last-ditch effort Krang activated the jets but the Metalhead exosuit's grip was to tight for him to get free. Krang once again ripped everything from the bottom part of the mobile suit, but made sure that he didn't destroy the life support system. On the other side of the room, the turtles watched as Donatello kept overcharging various parts of the remains of Krang's suit until it began to shake. The turtles pushed the exosuit down into the tunnel & watched as it disappeared from sight. A few minutes later the building rocked with force. Mortu approached the turtles with Krang's container tucked in his arm. Though his suit was still pristine it was obviously running on fumes. With some regret the turtles handed over their remaining handheld devices to power up the suit & Mortu opened another portal.