Aliasing やとすけ → andya
Link to alias

Reason:

Same artist.
Though I have no idea where the andya nick is from. Transliterated would be yatosuke and his twitter nick is yatton7.

So I would've never thought to search for andya. Had to reverse search a couple of images to find out how he is tagged here. :/

EDIT: The more I look into it, the less valid the Andya nick seems. The artist doesn't seem to use it anywhere, and most results on Google direct to here. Might be better to use yatosuke as the main tag instead.

やとすけ = yatosuke
yatosuke != andya

I think I figured out where the name must have com.

• saucenao for a very old post shows "やと"
• Putting "やと" that into Google translate transliterates it as "yato" and translates it to English as "Ya and".
• The word order was swapped at some point, "and Ya" and thus andya

Either way, they definitely all refer to the same artist. Since yatosuke is the transliterated form of the name, I've made following changes:

• Alias: andya -> yatosuke (approved)
• Alias: やとすけ -> yatosuke (approved)
• Alias: やと -> yatosuke (approved)