SPOILER WARNING: This article contains major spoilers for “Crisis on Earth-X, Part 4,” the fourth episode of this year’s Arrowverse crossover.

The Arrowverse just gained a new hero. In “Crisis on Earth-X,” this year’s Arrowverse crossover, Citizen Cold elected to remain on Earth-1 rather than return to his homeworld Earth-X.

“I think I’m going to stick around here for a little while,” Citizen Cold said to The Ray as Cisco “Vibe” Ramon prepared to breach them both back. “I won’t stay here forever. I will come home to you. Promise.”

RELATED: Crisis on Earth-X: The Ray & Citizen Cold’s Connection Revealed

Ray offered him a sad smile and replied, “Okay.” With an exchange of “I love you,” they shared a kiss goodbye, and Ray stepped through Cisco’s breach to return to Earth-X.

Unlike The Ray, who is originally from Earth-1, Citizen Cold is native to Earth-X. As shown over the crossover, this version of Leonard Snart is more of a hero than his thieving Earth-1 counterpart; Leo is much more sentimental and rule-abiding, a lover and a fighter.

This new development, of course, opens up Wentworth Miller’s fan-favorite character to appear on the other Arrowverse series: Supergirl, The Flash, DC’s Legends of Tomorrow and Arrow. Miller started out as Captain Cold on The Flash, before becoming a full-fledged member of the Legends in Season 1, where he heroically sacrificed his life to save his team.

RELATED: Crisis on Earth-X Alters Key Relationship On Another Earth

Earlier this month, Miller announced he will make his final appearances during Season 4 of The Flash and Season 3 of Legends of Tomorrow before saying goodbye to his role for good. It is unclear where or when he will exit the Arrowverse.

This year’s four-part crossover “Crisis on Earth-X” will air across two nights, beginning Monday, Nov. 27 with Supergirl and Arrow (on a special night for one week only) and concluding Tuesday, Nov. 28 with The Flash and Legends of Tomorrow.