Indeed. Now, Bob is a fickle creature, interested in nothing but amusing himself. However, if Black Battler manages to influence him, or maybe even defeat him, a very interesting scenario could be created. Beatrice seems to be an incredibly powerful witch, which means the B Battler is probably quite dangerous himself. Furthermore, as he does not use the Red Truth, which Bob can counter by warping truth, he is far more effective against the Chaos Shard. If he could figure out how to kill Bob, that could end up being a rather interesting fight.