Typically, when one won a fight, it was customary to stop the abuse of their foe...but this wasn't a traditional bout....and Faust was far more than a foe. It had become personal; and now that it appeared that the old bully was dead - he still had lots of rage he needed to release, and there was one more target he had in mind.
That giant serpent that started all of this (well, in his mind it started it). Had that thing just left him alone, he'd still be relaxed and probably neck-deep in women by now as the moon started to settle near the horizon of the sea.
He didn't have much time now, and so he wanted to make the best of what was left - and he had a lot he wanted to do to his original captor, who hadn't leapt below the waves yet.
