Complex sentence: The new Venom defeated Flag-Smasher cohorts, but then succumbed to his Symbiote's murderous tendancies, ripping off Flag-Smasher's right arm.
Split into simpler sentences: The new Venom then succumbed to his Symbiote's murderous tendancies. After killing Flag-Smasher's cohorts, he then bit off Flag-Smasher's right arm.