Not sure where he got the word 'desolater' when KJV says 'desolate'.
And he shall confirm the covenant with many for one week: and in the midst of the week he shall cause the sacrifice and the oblation to cease, and for the overspreading of abominations he shall make it desolate, even until the consummation, and that determined shall be poured upon the desolate. KJV (Dan 9:27)
And he shall confirm a covenant with the many for one week; and in the midst of the week he shall cause the sacrifice and the oblation to cease, and because of the protection of abominations there shall be a desolator, even until that the consumption and what is determined shall be poured out upon the desolate. Drby (Dan 9:27)
And he shall confirm a covenant with the many for one week. And in the middle of the week he shall cause the sacrifice and the offering to cease. And on a corner of the altar will be abominations that desolate, even until the end. And that which was decreed shall pour out on the desolator. LITV (Dan 9:27)