apollyon
/ˌæpəˈlaɪɒn/Definitions
1. noun
a powerful opponent or adversary, especially in a spiritual or metaphorical sense
“The apollyon of her doubts threatened to derail her decision to pursue her dream.”
2. noun
the king of the locusts, a monstrous creature in the Book of Revelation
“In the biblical passage, the apollyon was a terrifying beast that brought destruction and chaos.”