What about Caster's master in Unlimited Bladeworks. With Caster reinforcing his fists, he was able to lay a pretty solid beat down on Saber. Even if he did get the first shot due to surprise, I don't find it very hard to believe he could go head to head with Saber. My character is the same, but if you were to throw a Beserker at him, he probably wouldn't hold up very well, and some other abilities would definitely be a bit too much for him to take on. Plus, I don't expect him to beat any of the servant's he's facing, unless they re really weak, just fight them until Caster able to deal with them. Plus, since this Caster can create something like mechanical golems, he probably won't be fighting alone.