The Fallen Star in Act I is not in and of itself demonic, so why did it crashing into the Tristram Cathedral cause minions of hell to burst forth? Was it intentionally directed to impact there?
If it simply broke some seals containing all this badness, the odds for it to hit just so seem astronomically small; did some demonic influence guide it like a JDAM from Heaven (but controlled by Hell)? (I'm part-way through Act II; so I know what the star's made of; is more revealed about the impact going forward?)