Revelation 4:9

4:9 And whenever the living creatures give glory, honor, and thanks to the one who sits on the throne, who lives forever and ever,

Revelation 17:10

17:10 five have fallen; one is, and the other has not yet come, but whenever he does come, he must remain for only a brief time.

tn Here καί (kai) has not been translated since English normally uses a coordinating conjunction only between the last two elements in a series of three or more.

tn That is, one currently reigns.