Tomorrow's Ace is You! (明日のエースは君だ! Ashita no ēsu wa Kimida!) is the 52nd and final episode of Ultraman Ace.
Yapool created his strongest choju called Jumbo King for the final attempt to kill Ultraman Ace, created by combining the souls of the deceased choju: Unitang, Cowra, Mazaron Man and Mazarius. Yapool (in the form of The Child of Alien Simon, and in the company of TAC) unleashed Jumbo King. Yapool appeared with the dead choju and combined with them to form Jumbo King before them. TAC quickly opened fire, but Jumbo King's hide made him impervious to their assault and during the scuffle, Hokuto was injured by the choju. With Hokuto out of the picture, Jumbo King vanished.
Later Yapool released Jumbo King again, this time in the heart of a city. With only TAC as its opposition, Jumbo King easily withstood their assaults and downed them all at once when they tried to ensnare him with a net. With the city leveled from his choju's rampage, Yapool recalled Jumbo King again. The next day Yapool unleashed Jumbo King again, this time in the city where Hokuto was hiding out in. Endangering the lives of several children, Hokuto was quick to evacuate them while TAC tried to destroy the monster with a newly crafted weapon they've created (which failed). Shortly after killing Alien Simon for revealing his true nature, Hokuto transformed into Ultraman Ace for the final time to battle against Jumbo King. Unfortunately, Jumbo King's size and durability was too much for the Ultra to handle and Ace was quickly overpowered. Motivated by the words of all his friends he had made, Ace didn't give up and continued fighting. Ace then fired his Metallium Ray at Jumbo King's head, weakening the choju enough for Ace to use the Guillotine Shot, decapitating the Choju and killing it. With Jumbo King dead, Yapool's life and his reign of terror on Earth had finally ended.
- Ultraman Ace Volume 13 features episodes 49-52.