Kenpachi starts without his eyepatch
Scenario 2: Kenpachi has his eyepatch on
This is pre-Unohana training Kenpachi
I believe that her ability would be what takes him out.
he Explode (爆撃 (ジ・エクスプロード), Bakugeki (Ji Ekusupurōdo); Japanese for "Bombing"): Bambietta has the ability to turn anything that her Reishi and Reiatsu touches into a bomb. Because of this, her explosive attacks cannot be blocked. However, her attacks can be deflected before the explosion occurs, if hit by a sufficient force. By using her power, Bambietta can set off explosions within her close vicinity. Additionally, she can generate explosive energy around her, which radiates outward in a large globe and causes heavy damage to her surroundings.
When this is activated, a substantial amount of Reiatsu is released, resulting in the formation of a towering column of energy that ends in a large Quincy Cross, from which Bambietta emerges in the Quincy: Vollständig after the column shatters. In this form Bambietta develops large wings and a halo in the shape of a pentacle floating above her head. According to Giselle Gewelle, because of her idiocy and the power she gains from this form, Bambietta could end the whole battle against Soul Society before it really starts.
However if Kenpachi gets around that, than she is dead
@taichokage: I don't think she would have much trouble dealing with his speed. IMO she only went down so easily because she went up against someone who was immortal, which is a pretty bad matchup for an explosives fighter.
All the same, Kenpachi did take down 3 sternritter (one at a time, sure, but still). Though they seemed weaker than Bambi (never thought I'd say that), it's still impressive.
For now I'd say it could go either way. Even if Bambi does win, Kenpachi will definitely give her a tough time (it'd take a ton of her explosions to put him down).