Mivali stands for Mirah X Revali
This Ship takes place in the Zelda/BOTW Universe

Mirah was secretly in love with Revali for a long time, but she never expected to have a chance to come a little closer to him, nor that he would even notice her. She wasn't even very interesting in her own eyes, so she did not rise any hopes. For her own enjoyment, she learned how to use a bow, which is rather unusual for female Ritos.
When Revali accidentally watched her at her secret training spot, a little spark of interest was born. He kept an eye on her every now and then, trying to find out more of her. When he started to make the first step, Mirah was so shy she couldn't even get a word out when he was standing right in front of her. She often tried to escape the situation then.
It was impossible for her to understand that the great Revali who was actually busy enough to be glorious, would waste his precious time on someone like her. But to her surprise, he kept rising a wing to her, until she finally took it.
They will have a son, Yoru, who becomes a warrior fighting for Hyrule during the great calamity.

Offspring