Hmm, if we're talking about Bayonetta 2's version of Bayonetta, then she stands a good chance.
Both Bayonetta and Kratos have:
- A vast arsenal of incredibly dangerous weapons of supernatural origin. Bayonetta has the advantage of a large arsenal of ranged weapons on her side, including the ever-trustworthy Love is Blue. I'm not really sure how Kratos would fare against magical firearms.
- Supernatural strength. Each of them survive attacks that would turn regular humans into meat salad, and they are both much stronger than their appearance shows. Bayonetta gets a bonus in her agility and dexterity, as well as heightened senses.
- Magic, though each of them uses it in different ways.
- "Rage Mode". Kratos' Rage of the Gods/Titans, and Bayonetta's Umbran Climax. I would say Bayonetta has an advantage in this area, as Umbran Climax causes every attack she makes to also summon a Wicked Weave, with certain combos summoning an Infernal for an AoE attack. She's also able to use it more often than Kratos can use Rage of the Titans (at least, in the first game, anyway. I don't know if its charge time has improved in the other games, but it was real fuckin' slow to charge from what I remember), Bayonetta also gets a small health regen while in Umbran Climax.
I think I have to hand this to Bayonetta.
While Kratos has plenty of experience fighting massive beasts and powerful gods/goddesses, Bayonetta has superior mobility and plenty of support abilities to back her up. If she can simply play keep-away while firing on Kratos with Kafka (homing arrows that poisons their target), Kratos won't even be able to lay a finger on her. I'm gonna assume that we're not even including the various Accessories that Bayonetta can use to further augment her fighting abilities, Moon of Mahaa-Kalaa anyone?