Even from the very beginning of Primarch creation, custodes pretty much likely distrust Space Marines

Space Marines vs. Custodes: A Hilarious Warhammer 40k Meme Breakdown

Meme Description

This Warhammer 40k meme had me snorting recaff out my nose with its spot-on humor about the Adeptus Custodes! It’s a classic setup: the top text reads “Space Marines: Simply Existing,” setting the stage for the golden boys’ reaction. Below that, “Custodes:” is paired with a hilarious Attack on Titan screenshot of a wide-eyed, panicking character looking like they’ve just seen a Titan-sized heresy. The image captures the Custodes’ over-the-top paranoia perfectly—they’re always on edge, ready to yeet anything that even smells like it might disrespect the Emperor. It’s as if the Space Marines’ mere existence is enough to make a Custodian grab his Guardian Spear and start interrogating a Dreadnought for “suspicious vibes.” For any 40k fan, this meme nails the Custodes’ neurotic loyalty to the Throne, and I can’t stop laughing imagining them side-eyeing a loyal Ultramarine like he’s about to join the Black Legion!