Now, I have never read it, but nothing I have read about made it look good. The Beast Saga contains GIANT and WELL-SPOKEN Orks invading Sol with a GIANT MOON and having human slave camps ft. breeding programs.
There is no amount of quality writing in the world that would make the awful premise good.
But it's furthermore sprinkled with trash like:
IF get wiped with a single survivor left.
And
Ullanor is Armaggedon and also the ork homeworld, so that's why they keep invading.
This was the worst thing to strike 40K fluff since Daemonhunters killed some Sisters of Battle to coat their armor in their demon-repellant blood (and also the whole "leave no witneses" thing)


