@Astolfo: So far I've been tagging images with the...

Astolfo
2018-04-11T16:20:21-04:00

So far I've been tagging images with the original copyright a character is from, UNLESS a different copyright is implied in the picture.
For example, I'd tag a picture of Mordred with fate/apocrypha unless she is in her Grand Order outfit or with FGO characters where I'd only tag it as fate/grand order.