It's is the conjunction of it is. Its is the posessive of it.
Can't edit this page so...
There is a minor grammatical error in the following sentence:
" The Nightbringer was ultimately buried ten kilometers under the planet of Pavonis' surface, entombed there when its flagship the Bringer of Darkness, a Cairn-class Necron tombship, was badly damaged by an unknown alien fleet and crashed on 60 million years before the present. "
It looks like this was supposed to say "crashed on the surface 60 million..."