Somari Memia is a Sonic Mania repaint project.
Origins EditDaytin and 20 are gay and they made it xd.
Mairusu is a youtuber who (at least to the crib) makes terrible videos based on FNAF and Undertale, AKA cringe city.
He made a video showcasing the mod without permission, nor was the mod even released officially yet. It was made even worse when the video was very unfunny. Efforts to have him remove the video have be unsuccessful.
This has also spawned the sub-meme "And it was so well made", which was a comment made in the video about how the game forgot 3-D segments, which makes sense since the mod wasn't done yet.