Amalgam Comics JLX In Their Own Book At Last #1 April 1996

After being framed by Will Magnus, the Mariner is captured by S.H.I.E.L.D. and the Judgment League Avengers, Mister X assembles a team to free their fellow Metamutant. The team is composed of Apollo, Runaway, Nightcreeper, Firebird, Mariner, Wraith and Mecury.

After successfully freeing Mariner, the JLX flees to the safety of Atlantis, but before reaching their haven, the JLA cathes up and a battle ensues. While holding their own against the likes of Captain Marvel, Super-Soldier, Angel Hawk, Canary, Goliath, Hawkeye, and Dark Claw, the JLX are able to slip away after a distraction by Angel Hawk, a fellow Metamutant in secret.

Upon arriving in Atlantis, Mariner is shocked to find it in ruins, and the team runs into Will Magnus and his Metamutant hunting robots the Sentinels. During the fight, Mister X reveals his true identity, that of a Skrull named J'onn J'onzz and manages to defeat the Sentinels.