Unknown Soldier (Ace Comics)

The Unknown Soldier is a fictional superhero character who first appeared in Our Flag Comics #1 (August, 1941) from Ace Comics.

Publishing history
Our Flag Comics only lasted for five issues — the last issue was dated April, 1942 — but by then The Unknown Soldier was transferred to the Ace title Four Favorites, appearing from issue #4 (March, 1942) to #20 (November, 1945). After that, he fell into the public domain.

In 2008, the Dynamite Entertainment one-shot Project Superpowers: Chapter Two Prelude stated that this character — now renamed Soldier Unknown, to avoid trademark hassles with DC Comics — would appear in the second volume of Project Superpowers, as part of a team of Ace heroes called The Super-Mysterymen (named after the defunct Ace title Super-Mystery Comics).

Ace Comics
The Unknown Soldier is a mysterious being who claims to be the physically manifested spirit of all who died to protect the United States; during World War II, he came to the aid of American soldiers whenever they needed his help. He wears a costume patterned after a U.S. soldier's uniform (complete with garrison cap) and a mask; he possesses super-strength and the ability to fly, and he carries a "nitro gun" that fires explosive bullets.

Project Superpowers
At some point after the war, the Soldier was trapped in the mystical Urn of Pandora by the misguided Fighting Yank, along with dozens of other heroes; decades later, the Urn was broken and the prisoners freed. The Soldier and seven other heroes — Captain Courageous, Lash Lightning & Lightning Girl, Mr. Raven, The Sword, Magno, and Vulcan — were then recruited by unknown forces to form a team called The Super-Mysterymen; what part they will play in the modern world has yet to be revealed.