Miraculous Ladybug: King Dragon

A normal guy named Quinlan King lives with his boyfriend in Los Angeles, nothing special about him. But in another dimension, some superheroes are fighting a villain to save their home. But the battle cost one of the heroes' lives. Before she died she got sucked into a portal and was sent to another dimension. Meanwhile, Quinlan King was going on a walk while his boyfriend was working and minding his own business when he stumbles across a woman laying on the ground. He rushes to go help her as she is taking her last breaths.