Can I recommend thehometree to you for your Saber? I honestly love Playable EXTRA Saber, and she would be awesome to have in game! There is some slight power loss - mostly towards any fire-based abilities and massive amounts of weaponry - but hopefully that won't turn you off from the game! Hometree is a small, slow to medium game that picks up during events where characters are transformed into fairies and they try to find out how to deal while solving quests/riddles. While I can't offer you castmates from EXTRA specifically, we do have Saber and Shirou from the UBW route, Archer and Rin from HF route and myself as Illya as well as kid Gil from the magical girl spin-off.

If you're interested, please take a look! We also have our test drive here in case you want to try us out. Our AC is also rather light, having it be one post, log, or thread that's ten comments long. Hopefully you find the right game, regardless if you join us or not!