Isn't the artist Carnelian? Why is the Carnelian tag being deleted from these character's images and Yuuji Aoi being added instead?
Also this character is from the game Moldavite...
or there's something i don't know?

The images that are being tagged "Yuuji Aoi" are *gasp* NOT drawn by Carnelian. A glance at the Getchu page will reveal that the images in Moldavite are actually drawn by several artists, Yuuji being the main artist (also goes by the name "Drain Cherry"), while Carnelian is one of the extras. Most people tend to automatically mark an image as "Carnelian" when it remotely resembles her artwork. One of the more hilarious examples of this would be this image that was tagged as such when it has Yuuji's signature clear as day on the bottom right corner.

http://moe.imouto.org/post/show/8824/lilith-moldavite-yami_to_boushi_to_hon_no_tabibito

Then i'll undo the changes i did right away!
I was googlin information about Moldavite to be sure, but i found nothing.

Short of having a signed image, how else can you tell when it's Yuuji Aoi and not Carnelian?

cheese said:
Short of having a signed image, how else can you tell when it's Yuuji Aoi and not Carnelian?

By looking at it.

(Seriously what do you want me to say?)

Although in this case, I believe each artist is assigned certain characters, like they did for "Quilt". This character happens to be assigned to Yuuji.