Art by... no one, I believe? Look, I was minding my business, scrolling through X, and then I saw a video of this. It's a figurine of Artoria. Tried to find out if it's based on some drawing, and it doesn't look like it.

Check the artist or artists behind it, if you want:

いかさ (@ikasa_1225) / X

ЯIDE フィギュア作ります。次回WF2026S乳上は再販予定 (@ride168429687) / X

So... the plot is simple. You can either be another Master who took interest in her, or just a bad guy/villain who captured her and starved her out of mana. What you do next is up to you.

Also, I don't know much about the Fate series, since I've never watched it, so I'll try my best here.