He Who Made Dark is a recurring and overarching antagonist in the SCP Foundation series, he exists as an ancient deity who created the darkness and the archenemy of He-Who-Made-Light. He is equal to his enemy, and both of them are Boundless (Tier 0) in power. Both enemies exist as embodiments of light and dark. Both enemies have a harsh rivalry towards each other, but only He Who Made Dark is hateful to everything. And he was also the creator of the Scarlet Demon and Calamitous.