Whereas I felt that the Tyranids occupied that thematic design space first and better, as faceless alien dooms go - all the Necrons had going for them was 'but this faceless alien doom is also ROBOTS!!!111'. Even for a setting like 40K where an apocalyptic threat lurks behind every corner, the Necrons just had nothing interesting or unique going for them, and even their 'gods' were singularly unimpressive. Now they're Tomb Kings IN SPACE, like the Eldar are High Elves IN SPACE, the Dark Eldar are Dark Elves IN SPACE, the Orks are...Orcs IN SPACE, the Squats are
Dwarves IN SPACE eaten by Tyranids, so hardly unprecedented or out of place.
...didn't we have this exact arguement like 10 pages ago upthread, anyways?