I still not understand where Nyakingu got this work from; I've searched the entire internet and can't find anything

Sorry @Kemal_Ataturk, this is a third-party source. Do you know where the original video is?

thefoxne said in comment #2592239:

Sorry @Kemal_Ataturk, this is a third-party source. Do you know where the original video is?

It's from a promotional animated card collection from Bilibili. This marisa art in specific can't be found on the collection page, but is proven by this link that it was formerly part of it or it can be unlocked later in the collection. All nyakingu uploads are in fact, promotional Bilibili cards

Kemal_Ataturk said in comment #2592252:

It's from a promotional animated card collection from Bilibili. This marisa art in specific can't be found on the collection page, but is proven by this link that it was formerly part of it or it can be unlocked later in the collection. All nyakingu uploads are in fact, promotional Bilibili cards

oke thanks