His "swarthy darkness" line 5 suggests that Lucifer is darker than dark, he is a powerful being, he is stronger than the laws of nature. His blackness has no limits, the darkness of his body and the darkness of his soul can't be equaled / can't be matched / have no equal. In the same way, the burst is heard before the light is seen, he can reverse the laws of physics, his powers are supernatural. He also has the power to control snakes, to tame wild animals. Of course, the text doesn't speak about nice rabbits, it speaks about snakes which represent evil.

Incidentally, this being said, even if he did not have any supernatural powers, his mere physical appearance would be enough to make him invincible, for example with his "enormous wings" or his "armed hands and feet".