Como dizer "você apareceu do nada" em inglês

You appeared out of nowhere.

I was there and out of the nowhere you appeared.
[here an inversion, perhaps for effect, but I have noticed that with something to "complement" the sentence/idea, this inversions comes up.
In this case the "complementary" information is that "I was there..."]

http://www.azlyrics.com/lyrics/tylersha ... cards.html

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...out of the blue, to my thinking is more common to speak about things, happenings, events.
Not that I am ruling out the word with subjects, but with words like "out of the nowhere" or "suddenly (appeared)/all of sudden/unexpectedly/without warning" would be more used.
Again, it´s my opinion here, you can run a search and crawl within some search engine of your preference anyway.