Sentinel

A guard that never leaves its post is a fair description of Sentinel, an Exalted aura that asks for 60 million rolls on average at 1x luck, or about 6 million at 10x. It has no biome, no event and no side route, so every roll is a plain 1 in 60,000,000. The wiki lists it as obtainable since Eon 1-5.

The in-game text describes the most common military unit protecting a magically infused city, countless replicas walking the same patrol routes for a thousand years. The visual matches that cold discipline: a blue star on the face, one arm raising a spear or sword of blue energy, a shield held at the waist like Solar : Solstice, and blue energy with a glowing ball behind the player, reminiscent of Harnessed. The wiki also notes a strong resemblance to Exotic : Void. The cutscene opens on a slowly spinning dark blue star. It has no active ability. AndrewNursh is the credited creator.