In Buddygirl's universe, his name is Jaceon Pratass. His first major appearance was in the story, Memoirs of a Teenage Amnesiac, and in the other books in the Memoirs series, in which he was Kuki's boyfriend. He was dumped by her when he came to visit her at the Beatles house which was where she was living.
Another major role he plays is in A KND Parent Trap, in which he is Kuki's boss at the hospital and he forces her to marry him or he threatened her that he would go to child services and tell them that she neglects Yuki because she is always working.
He appears in a variety of one-shots and makes minor appearances in her stories in which 3/4 is the main pairing.
In Toonwriter's universe, his name is Chico Muñez, and he finally joins the Kids Next Door as a member of Sector Flashpoint.
Numbuh Phenon's UniverseEdit
In Numbuh Phenon's universe, his name is Antonio Fizz, and he is the son of Mr. Fizz. This was revealed in the story Mission: FLAT, where Ace helped Wally and Hoagie stop the Common Cold and the Interesting Twins from delivering a shipment of poisonous soda to the CCC. He is also paired with Lizzie in that universe, and has a son named Shirley.
In Gamewizard's universe, his name is Antonio Fizzuras, son of Mr. Fizz, and he's seemingly friends with Lizzie and Herbie, and has a crush on Henrietta. He and Lizzie fought together against the Irkens in Operation: GALACSIA.
In the one-shot "Looks", Ace told Henrietta he at first liked her for her looks, but later loved her for who she was.
During their teenage years, Ace got Henrietta pregnant with their future son, Augustus. During her pregnancy, Henrietta longed for the outside world again, so Ace promised to care for the baby while Heinie set out to have adventures. Henrietta went sailing with Marine and her Raccoon Pirates, but his wife soon returned to him as they raised Augustus together. The two also marry later, and Ace gets a job as an airplane pilot, and his co-pilot is Hoagie. When Augustus is 9 years old, he runs away from home and joins Henrietta's former crew, the Big Mom Pirates, captained by Henrietta's mom, so his wife leaves him again to go rescue him.
In The Great Candied Adventure, Ace and Hoagie fly the Sector V crew to Azultown as they're about to ship off to stop the Big Mom Pirates. They succeed in the end as Heinie returns with Augustus, and as they take their son to Knightbrace to fix his years of cavities, the couple rekindle their relationship.
In the 'KND: Universe', Ace appears in the story 'KND: Aggressive Tendencies', and through unknown events, he had become a teen pop star who had gained a powerful fanbase around the world.
Ace has orange hair that's brighter orange in the middle, shaped like 3 fan blades, wears sunglasses (similar to Numbuh 1's), a brown jacket, blue jeans, and white shoes.
Ace speaks with a thick Hispanic accent. He is very cool and laid back most of the time, and really smooth around the ladies. He shares a lot in common with Hoagie, as both love airplanes and chilidogs.
Ace is an extremely terrific pilot who greatly rivals Numbuh 2's skill in aerial combat. Although a non-operative, he can create worthy aircrafts out of scrap, and was one time able to modify his inner-tube to fly.