Complex sentence: Buffy shows up in time to find the dead body and the Ubervamp, but before Buffy has a chance to fight, the Ubervamp attacks her and Buffy gets hurt, running off in search of better fighting grounds and a useful weapon.
Split into simpler sentences: Buffy shows up in time to find the dead body and be attacked by the Ubervamp herself. Before Buffy has a chance to fight, the Ubervamp attacks her and Buffy ges hurt, running off in search of better fighting grounds and a useful weapon.