According to Lincoln in "Sleuth or Consequences", Ace is the world's savviest crime fighter ever. He is a man of few words, and fewer emotions, that fights for justice. It seems that he has super strength, and the ability to fly, but it's currently unknown if he has any other superpowers.
He uses a playing card-theme, and also his main weapon is a deck of playing cards, which he uses to call his entire deck of superfriends. His deck includes his trusty sidekick called One-Eyed Jack.
He's referenced many times in "Sleuth or Consequences". Lincoln cosplayed as him, because he was going to attend a comic book convention, but he is grounded after he clogged the toilet. Although he said that because he wanted to protect Lucy (who was the real culprit behind the clogged toilet) from her sisters' teasing, therefore, he couldn't assist.
Ace and his deck appears in the mini-comic "Deuces Wild!". In the comic, Lincoln and Clyde get the latest issue of the superhero, but before they can read it, they must change Lily's diaper. They do it in the style of Ace, imagining that they are Ace and his sidekick One-Eyed Jack respectively, Lincoln's sisters are Ace's complete deck, and the stinky gas monster is Lily's dirty diaper.
Ace is a very muscular, man with fair skin. He has brown short hair with a lock of hair hanging on his forehead. His costume is like a typical superhero costume: a red sleeveless shirt and shorts, a yellow belt, and a blue coat. On his chest he has a black spade with an "A" inside of it, which is his symbol. He also has one black bracelet on each wrist.
In "Deuces Wild!", he's wearing a red long sleeved shirt and pants, and instead of being black, his bracelets are gold. Also, instead of having brown hair, he has blonde hair.