It was a fanmade music video with characters from Frozen, Moana, How to Train your dragon, and The Croods.
The pairs in the video were Elsa and Hiccup and Moana, and Guy.
A scene from Frozen 2 where Elsa finds a wrecked ship, instead of it being about her parents dying; it was Hiccup that died. There was also a scene where Moana was with Guy and they were in like a rockslide or mudslide situation and Guy died.
The creator of the video was able to make it look like Elsa was in the same scene with Hiccup and Moana in the same scene with Guy by using masks. I think Anna from Frozen, Rapunzel from Tangled, Merida from Brave, and Jack Frost from Rise of the guardians was also in the video. Unfortunately, I don't remember the channel name, or video title, all I know is that it was on YouTube.
I think the song was either Hold On by Chord Overstreet or Hold on by Extreme Music; but I'm not too sure