Okay, show of hands, who knew this was coming eventually.
Mako was filled with adrenaline. Her mind was too focused on the prize, focused on the end game, too driven by the power she got from her new two-star uniform to think clearly. She cracked her new bat against Ryuko's head, sending her best friend flying into a nearby stone wall. Mako could tell on some level that what she was doing was wrong, but everything just felt normal to her, especially with her family cheering her on from the stands.
"Mako...please stop. I don't want to fight you.." Ryuko said, standing shakily. "I wouldn't want to fight me either!" Mako shouted, rushing forward and punching Ryuko in the face, her massive brass knuckles sending Ryuko back into the wall, knocking the wind out of her as Mako picked the bat back up, swinging it at Ryuko and sending her into the air.
Ryuko managed to land on her feet, but was bleeding from the corners of her mouth. "Mako, y-you don't have to do this." Ryuko said, trying desperate to get through to her friend, ignoring Senketsu's urging her to fight back.
"I know I don't have to." Mako said, a wicked grin spreading across her face, "I want to!" She shouted, rushing Ryuko again. Ryuko braced herself, prepared to block the bat again, but at the last moment Mako dropped the bat and switched to her brass knuckles again, uppercutting Ryuko and sending her thirty feet in the air before she fell back to the ground; landing hard on her back as the wind was knocked out of her.
Mako stood over Ryuko, drunk on her new found power over her friend. She raised her feet, stomping the large, heavy shoes of the uniform on Ryuko's stomach. Ryuko gasped out in pain as Mako repeated the action, stomping on her again and again before kicking her in the side and sending her rolling across the arena field.
Mako grinned again, getting an idea. She walked back over to where Ryuko, barely conscious, was laying on her back. She removed what she was wearing underneath her fight club uniform, showing that the power she'd gotten from it was also effecting her cock, which was now just under two feet in length, twice as thick as before, and solid as a rock as she looked at Ryuko laying beneath her; her life-fiber drugged mind getting a sick pleasure from having complete control over her friend, even while she was wearing Senketsu.
The crowd all went wild, as up to that point no one but Ryuko and Mako's family knew that Mako was a futanari, though the realization did make a lot of things suddenly make sense to them.
Mako grabbed Ryuko's legs, forming them open and pulling aide the part of Senketsu that covered Ryuko's pussy. "Yeah! Fuck the shit out of the whore sis!" Matarō cheered, just as drunk on the power and high-life as the others. "Make the bitch scream honey!" Sukuyo called with a wave. "Break the little slut dear! Make us proud!" Mako's dad added with a smile.
Ryuko couldn't believe that this was happening, but couldn't will herself to get angry. The fight club was her idea to begin with, and she'd been the one who forced Mako to be in charge of it. She'd practically handed Mako the two-star uniform herself.
"Do it Mako." Ryuko said meekly, "If...if you really feel like you have to, if you really want to, do it."
This caught Mako off guard. She'd been expecting Ryuko to tell her not to, to scream and yell at her to change her mind and stop fighting, but this...Mako shook her head, ignoring those thoughts.
"Shut it bitch!" Mako hissed, kicking Ryuko in the side and glaring when Ryuko just smiled up at her. 'She won't be smiling for long.' Mako thought with a smirk, lining up her massive cock to Ryuko's pussy and thrusting her hips forward hard.
Ryuko cried out in pain from just the tip, and even with all Mako's enhanced strength, it took her some real effort to force much more in. Mako grabbed Ryuko's wrists, pulling hard and forcing more and more of her cock into Ryuko, stretching her pussy and making her stomach bulge by the time she was two thirds to the base. Mako grinned, feeling that she'd bottomed out in Ryuko, but she wasn't close to done.
With one more powerful thrust, Mako hilted herself inside Ryuko, who couldn't even speak anymore. Mako paused for a moment, enjoying the feeling of Ryuko's body squeezing around her cock before she started moving, pumping in and out at as fast a pace as she could at first, which wasn't very fast at all, then gradually adding more and more force to her movements to pick up speed.
In a few minutes, she was fucking Ryuko's pussy and womb to ruin, laughing and getting rougher when she saw the tears streaming down Ryuko's face. Mako picked up her bat, letting the tip of the glowing red nail wedged in it trail over Ryuko's tits, threatening to cut into her as she fucked her harder to make her cry out more. After a few moments, Mako let the nail tip sink into Ryuko's skin, leaving a shallow but painful wound. It was barely a wound at all, hardly bleeding, but it make Ryuko scream out in pain, so Mako did it again and again, leaving marks all across Ryuko's body as she destroyed her stretched out pussy.
Mako came after twenty straight minutes of this, completely filling Ryuko's pussy with burning hot cum, a lot spilling out out her pussy and pooling beneath her when Mako pulled out. Ryuko's stomach actually expanded from the amount of seed she'd been filled with. Loving the sight, and still being hard as a rock, Mako picked Ryuko up and threw her against the stone wall of the arena nearby.
Ryuko couldn't really stand on her own anymore, being in far too much pain, so Mako held her up as she lined her rod up to Ryuko's small, tight asshole, grinning as she listened to the crowd cheer her on.
"Do it Mako." Ryuko said softly, "If you feel better because of it, then do it."
Mako faltered again, pausing. It took her longer to shake off the momentary confusion this time, but she was able to shrug it off nonetheless and focus of ruining Ryuko's ass.
It took almost as much effort to fit Mako's tip inside her ass as it had taken to fit her whole cock into her pussy, by Mako managed to get halfway inside Ryuko clenching anus after about ten minutes. Mako picked Ryuko up, using gravity as she yanks Ryuko's hips down and thrust up into her. Using this method, she was able to ram her entire length into Ryuko's ass, Ryuko's eyes glazing over and her body going limp in Mako's grip.
Mako didn't care. Her cock was still hard, and she could hear her family, hear the whole school, cheering for her to keep fucking Ryuko until she broke. So she kept going, prying her cock out of Ryuko's ass and slamming it back it with all her might. After almost half an hour, Mako reached her limit again, letting out a torrent of cum into Ryuko's ass, filling her to the brim and actually pushing her off Mako's cock.
The rest of Mako's cum covered Ryuko's body. Mako looked into Ryuko's eyes, seeing that Ryuko wasn't even looking at anything anymore, just staring blankly up at the sky. Angered by this, Mako went over, picking her bat back up and hitting Ryuko with it again, and again, and again, tears beginning to well up in her eyes as she saw how weak Ryuko was now.
"Go sis!" "It's almost over!" "Finish her off dear!" Mako's family called to her. Mako nodded, lifting her back, putting all her force into one last strike aimed at Ryuko's head...but managing to stop just before it actually hit. :Why aren't any of you telling me to stop?" Mako questioned her family, sobbing as she did, "She'll die if I keep hitting her.."
And from there it plays out like the rest of the episode.