The Lighting Spirit Element
It was a sort of attack that would be easily countered if one knew what was going to happen. But if the spirit master didn't, no matter how he tried to defend, he'd end up getting wounded by these fangs.
The deadliest part of these fangs laid in the venom they carried. It was a venom that had no antidote but one that could be made by the Grand Black Mamba member who initiated the attack himself.
In brief, once got hit, it was the end story for the spirit master facing any Grand Black Mamba. And the scariest thing was that just one hit was enough, and the Grand Black Mamba member would retreat, leaving his foe to his demise awaiting him by the venom running in his body.
William knew all this about the more terrifying relatives of Garlend at the outer world. But he assumed there wasn't much of a difference between the two relatives and acted based on that.
And luckily for him, he was correct about doing so!