TORTOISE
"And.. begin!" Midnight shouted.
The moment Midnight called a start to the match, Todoroki froze the entire narrow hallway. Stuck in ice up to their necks, the students from every class found themselves unable to move.
"C-c-c-can't feel my legs," Mina said through chattering teeth. "T-t-this is so not cool!"
"Can't you melt your way out?" Hagakure asked.
"I'd love to, but the acid would explode everywhere. Do you want acid exploding everywhere?"
"Point taken."
Yaoyorozu, not limited to one substance, decided to make antifreeze. Unfortunately, the antifreeze also froze. Bakugo, as freezing cold as he was, couldn't work up a sweat, Tsuyu fell asleep, Kaibara couldn't move his drills around even after he got them spinning, Kendo couldn't quite fracture the ice by expanding her limbs, and for all of their manly efforts, both Kirishima and Testutetsu found the ice harder than their craniums. Hatsume had plenty of babies to bust through ice, but they were all frozen inside her backpack. Everyone was helpless inside their icy cocoons.
Everyone, except Izuku. Overcharging his battery, Izuku heated enough to melt the ice around him and strode out of the slush.
"D-dude, we're friends, right?" Kaminari asked. "Get me out of here and I'll treat you to lunch for a week."
"I will, but first, I must complete this race. Good luck winning!"
Kaminari struggled, but alas, the ice didn't budge.
As Izuku jogged through the ice-covered obstacle course, he noticed the ice-coated zero pointer looming overhead. After finding that the average course completion time of his classmates was just over three months, Izuku stopped by the giant robot. He bit a hole through the foot and disappeared inside, eating his way through the zero-pointer's leg. Sometime later, Izuku burst out of the zero-pointer's chest, having grown thirty feet in length and sporting four dozen new limbs.
"Eraserhead, what are you feeding those kids?" Present Mic asked aghast.
"Robots, apparently," Aizawa answered dryly.
Once Izuku had eaten the zero-pointer, his body curled up on itself, fitting back inside Izuku's mouth. As the tail broke down, Izuku's body grew bulkier and taller, until he towered over the obstacle course. Three massive strides took him over the pitfalls, and he stopped at the minefield for a light explosive snack.
Once Izuku crossed the finish line, Midnight waved her flag. "Seeing how no one else can complete the race, I guess we have our two finalists! Since there's not much else to do, let's cut to the chase and watch them fight!"
As Todoroki stared up at his mechanical opponent, he said, "Maybe freezing everyone wasn't such a good idea."
Todoroki made a lot of ice. Izuku blew it up with ingested mines. Todoroki made more ice and froze himself solid.
"S-s-s-serves you right!" Mineta shouted at Todoroki while rescuers sawed everyone out of the ice.
As the crowd rioted and demanded refunds, Aizawa yawned and said, "Best sports festival ever."
487
And that's how you write the Sports Festival in under five-hundred words.