Who would win in a fight between these two?
Can Shiki beat Shirou?
Arc, assuming she's at least at 30% and not nerfed as fuck. Nothing short of a full Excaliblast is going to phase her, and she should outperform Saber stat wise in pretty much every area. It'd be like Saber vs Herakles again, only without Caliburn to save the day and Herakles suddenly has all his senses and can warp reality on a certain scale.
alice no takarabako draws some mighty fine mana transfers.
Not only is Arc stronger than Saber, she's also prettier, funnier and cooler.