Everything you have done in Cult of the Lamb was in the name of the One Who Waits. Unfortunately, you are asked to sacrifice yourself and return the One Who Waits' crown and power, but you can refuse and fight them instead. Here's how to beat the One Who Waits in Cult of the Lamb.
The One Who Waits Boss Guide – Cult of the Lamb
The One Who Waits is one of the hardest bosses to face in Cult of the Lamb, which makes sense considering this is the being who gave you your powers. The One Who Waits has two phases, each requiring different strategies and tactics.
The One Who Waits' first phase is simple as it primarily involves projectiles and spike attacks. Keep moving, and don't be afraid to dodge through the projectiles. When he starts charging up a spike attack, retreat outside of its range; other than that, dodge in and out and get your strikes when you can to defeat the One Who Waits' first phase.
The second phase for the One Who Waits is more complicated and challenging. You must defeat the three eyes that begin floating in the arena, which will also go underground. Each eye can fire projectiles in different ways, so be prepared to dodge various attacks. Additionally, rings of projectiles can spawn on either side of the arena and fly toward you.
Throughout this phase, your followers will occasionally drop Fervor. This is a good way to keep your Fervor charged and allow you to use Curses. Keep attacking each eye while avoiding their projectiles; eventually, you will defeat the One Who Waits.
Who is the One Who Waits
The One Who Waits is the being that saves you from sacrifice and grants you your power. At the start, not much is known about this deity, but you will learn that the One Who Waits was formerly the fifth Bishop of the Old Faith.
Shamura, another Bishop of the Old Faith, unknowingly put new ideas into the One Who Waits' head. As a result, he tried to change their ways, and ultimately Shamura and the other Bishops chained up the One Who Waits. Since then, he has bided his time, selecting champions to wear his crown and free him.