On the wedding day, the mermaid bride ran away

Atlantis princess Maris damages her body purifying polluted seas. Betrothed to Commander Eamon, she refuses the temple. He brings home her half-sister Sybil, who manipulates them apart. Tricked by Sybil, Eamon rips out Maris's scale. Heartbroken, she flees to the temple on her wedding day. The doors close. Eamon arrives too late—they break forever, and he lives with regret.