PSYLOCKE

In Uncanny X-Men #256 (1989), British telepath Betsy Braddock — fresh out of the reality-rewriting Siege Perilous — washed up on the island base of the Hand. Its leader, Matsu'o Tsurayaba, had just lost his lover Kwannon, a Japanese assassin left comatose and brain-damaged. With the six-armed sorceress Spiral's "Body Shoppe," they did the unthinkable: they swapped the two women's minds and souls into each other's bodies — and intermingled their DNA for good measure. The British Betsy woke up in the body of a Japanese ninja assassin.

Brainwashed into the Hand's service as "Lady Mandarin," Betsy was eventually freed from their conditioning by Wolverine and returned to the X-Men — but the swap stuck. Meanwhile Kwannon, wearing Betsy's original body, surfaced as "Revanche," convinced she was the real Betsy Braddock, and died of the Legacy Virus in X-Men #31–32 (1993) before the truth ever fully untangled.

The undo took almost three decades. In 2018's Hunt for Wolverine: Mystery in Madripoor #1–4, Psylocke's soul was trapped by the soul-devouring Sapphire Styx — and using Styx's own soul energy, Betsy rebuilt herself a brand-new body matching her original British form. In the final pages of issue #4, Kwannon was resurrected permanently and restored to her own original body too. 1989 → 2018: twenty-nine years to get everyone back where they started.