I recently became a VTuber using my character as my model, should all my art containing this character beforehand have the VTuber tag added?

The description about the tag is a bit vague and that's my interpretation of it, but wanted to know for sure.

Thanks!

It's a bit ambiguous, and I'd say it depends if your character, nova-aurora, primarily exists as a vtuber model. Characters like Sonic the Hedgehog and Ruby (from RWBY) do exist as vtubers, but those characters would not be tagged as such, because they primarily exist in other forms of media.

Regardless, since vtuber is a copyright tag, it falls under "Tag What You Know": as character owner, what you know about your character is unique from anyone else. Do you feel that all the art of nova-aurora representative of NovaAurora the vtuber? Or to ask from another angle, would you expect someone else familiar with both all art of nova-aurora and NovaAurora the vtuber to tag all posts of the character with vtuber? If yes, then it would be appropriate for all art of the character, including older ones, to be tagged with vtuber. If no, and some art is distinct from the vtuber avatar, it could be appropriate to have two separate character tags (for example: "nova-aurora" and "NovaAurora_(vtuber)") with only one of them tagged with vtuber.

That's fair enough, thanks for the input!