Nono's super-strong stuff isn't relevant because she is pretty much not allowed to use it at all in the RP.
The exception is IF we ever get a scenario where she has that much room, enemies that warrant it, and I okay it, which is extremely unlikely.
The agreement for her acceptance was that she can't use her overkill attacks because of collateral damage.
I'd also like to point out that, out of the characters mentioned as being stronger than her... Samurai Jack has the best chance because he's so incredibly skilled he could easily fight Saber. There's certainly plenty of ways to hurt her in the RP, but pure magical attacks? Kazuma's not looking good in that department given Saber's magic resistance. ^^;
But this is the reason SE mooks have magically-enhanced laser gun things, so they can hurt characters like Saber who have extreme resistance to mundane attacks and magic.
I was out for a while so I haven't had a chance to look at any bios as well. ^^;
Um, you perhaps never heard about no limits fallacy. which is both good and bad, I mean internet arguments about which fictional character wins are far from the nicest things to read.
Caster can actually make a large scale spell which would overwhelm even Saber's magic resistance. She did it in Fate/Hollow Ataraxia.
Also you forget that magic resistance doesn't work against Noble Phantasms and generally against higher forms of magic.
I am the representative of a top class nature spirit. Think of Arcueid or perhaps an entity closer to Gaia.
I control wind by sheer willpower so it cannot be sabotaged the way like magecraft does. If anything it's closer to the normal attacks delivered by a Servant.
Similarly I have absolutely no problem to harm spirits, even though Saber actually doesn't count as one. She's still kinda alive and that's why she cannot turn into spirit form.
Even if we discount all these Kazuma is ridiculously more powerful than Caster so even by brute force he can tear through Saber's defenses at will.
Given the interdimensional BS Kazuma can do I doubt even Avalon will be helpful.
Or just kill her via countless indirect means. Including turning Saber's Barrier of the Wind King against herself.
So yeah, perish the though.
And I'd rather not wish to discuss any further how allies are supposed to murder each other.
Like I said, these kind of discussions have no point. I merely mentioned the standing of powers as per their original feats from their native universes. I kinda wish now that I kept my mouth shut.
Anyways, RP-wise I find it better if I don't just stomp my enemies even if I can make a reasoning why Kazuma is capable of that.
This is the difference between narrative and the objective analysis like what VS debates (mostly) try to do.
I play for the entertainment.