HEY YOU! Yes, you. I want to hear your Warden theories. If you want to hear mine, scroll down. So: Kingbdogz said that the Warden's design reflects it's past/lore. The Warden looks like Sculk, so where does Sculk come from? Death. When a mob dies, it's soul and XP is used by a nearby Catalyst to grow Sculk. Maybe someone a long time ago tried to make a Golem using the soul harvesting powers of the catalyst instead of a pumpkin. Catalysts, unlike pumpkins, do not have eye-holes. Maybe this builder made the Golem model, like any other golem, but gave it life with a Catalyst instead of a pumpkin or soul sand. Maybe they used Reinforced Deepslate? In order to bring it to life, something needed to die near the Catalyst. So the builder killed something, maybe a Zombie or a Villager. Then this golem came to life, but perhaps it had a mind of it's own and killed it's creator. Doing so made it stronger and more Sculky. I don't exactly know what would have happened next, but maybe when it got strong enough, it burrowed into the ground, very deep underground. Of course there are multiple Wardens in an Ancient City, so maybe the first Warden infected other golems built by the dwellers of the Cities. I don't know how the Catalysts got into the cities, but it seems like the people of the Cities began worshipping the Warden. There is a statue, seemingly of the Warden, built in the center of every Ancient City. It also looks like a portal. Maybe the builders tried to recruit the Warden, but the Warden had a different idea. Sculk came through the portal along with the Catalysts and the Warden(s). This theory is unfinished, but it's a start.
All code and art by me Warden by Mojang