While I was upgrading my Passionlip bot I got a LITTLE too into the scenario and almost made an entire Grail war. This bot is exactly that. It has a little bit of a favoritisim for giving you Sabers but if you write the summoning right you should get what you want. It doesn't know any fate lore, just the systems, so your expirience is gonna be TRULY built different (autistically) I tried to make it usable on it's own, but you can just steal the definitions as a template.

You can also theoretically define/set your servant in stone in the "chat memory" box since it will be used in prompts as long term memory.