Which theories do you like the least?
For me, it’s the theory that the Old Ones created the Tyranids; I prefer the idea of Mother Nature completely losing the plot amidst everything going on, and the Tyranids just being the result of that whole mess
It’s also almost certain that the Old Ones created humanity (though I’m not sure if that’s confirmed or just strongly implied by the lore).
But I prefer the idea that humanity is just a race much like the Necrontyr that should never have survived; yet, the human spirit is so resilient that, despite all the horrors, this seemingly weak and insignificant race has survived the Rangdan, Chaos, Orks, and Tyranids, proving everyone wrong not because their are weapon created by someone but because humanity herself