This chapter seems to obscure more than it reveals. He identifies a harlot, horns, heads, beasts and yet for centuries no one has been able to positively identify them -- but, not for a lack of trying.
Everything is now out of control. A harlot riding on a scarlet beast is defiling the nations with her immorality. This seems like one more powerful player lined up to oppose God. She is drunk with the blood of the martyrs (Rev. 17:6), not good. Add to that the sequence of kings that oppose God, Not good either.
They make war with the Lamb, and he conquers them. And, (Rev. 17:17), God puts in their hearts to carry out his purpose. Without their knowing, God directs their opposition toward his own goal. Wow! God is amazing and sovereign to the end.