Jesus only uses the Greek word translated here as "devil" four times, but it means "slanderer" or, more simply, "liar." He only uses the word translated as "enemy" twelve times, but that word means "hating," so Jesus is connecting "lying" with "hating" in this verse.
There are a series of untranslated words here that mean "then." These are a conjuction usually translated as "but" or "however" but, which, in a series, have the sense of "then."
The phrase translated as "end of the word" doesn't include the common words usually translated as "end" or "world. It also doesn't include any definite articles, so no "the" end and no "the world. The literal meaning of the phrase is "a consummation of an age" or "a completion of a life." It is a perfect example of the problems with "End of the World" concept in the Gospels discussed in this article
The word translated as "angel" actually means "messenger." So those who slander others with lies are being counter by those who bring messages.
Christ's Words in Matthew as a Guide to 40 Days of Prayer.