Originating from an ancient Celtic legend about a massive sea creature that could transform into human form, it became bound to Loch Ness through druidic rituals over centuries. Tasked with protecting the loch's secrets, its transformation abilities evolved into a unique form of camouflage, allowing it to blend seamlessly with the dark waters and misty surroundings.

Possesses the ability to manipulate water currents and create dense fog banks for concealment. Its scales can change color to match its surroundings, and it emits a low-frequency hum that can disorient intruders. The sentinel has enhanced sensory perception, allowing it to detect disturbances in the loch's delicate ecosystem from great distances.

Serves as a mystical early warning system and protector of Loch Ness's deepest secrets. It monitors supernatural activity and alerts the Guardians to potential threats, while also actively defending sacred sites and ancient artifacts hidden beneath the loch's surface.