Cruss is a character from the manga and anime series Beet the Vandel Buster, specifically appearing in Beet the Vandel Buster Excellion. He is a member of the legendary Zenon Warriors, a group of elite Busters who fought against the powerful Vandels. Cruss is depicted as a male adolescent with black eyes and shoulder-length red hair, often seen wearing a headband, a coat, and carrying his signature shield.

Before the events of the main story, Cruss participated in a fateful, immense battle against the Vandel Beltorze alongside his comrades Zenon, Laio, and the others. During this conflict, Cruss suffered massive injuries when Beltorze used a dark attack to slice his arms. The battle concluded in a cataclysmic clash that scattered the Zenon Warriors through a gap in space. Cruss survived but was left with severe wounds and complete amnesia, losing all memories of his past as a warrior.

Years later, Cruss is discovered living in the distant city of Bekatrute under the alias Cain, still suffering from his memory loss and injuries. He is the original owner of the Crown Shield, a legendary Saiga (a weapon forged from Divine Power) known as the world's strongest shield. At some point, he passed this shield to the series protagonist, Beet. When Beet and his team of Busters arrive in Bekatrute, they are attacked by monsters sent by the Vandel Garonewt. During the ensuing chaos, it is revealed that the person in Cruss's room is merely a Drawman decoy; Cruss himself has been captured.

Cruss's role in the story becomes central during the Garonewt Arc, where he is used as a hostage and a living shield by the Vandel Garonewt to prevent Beet from attacking directly. Even in his weakened and amnesiac state, Cruss demonstrates a selfless and courageous personality, ordering Beet to kill him along with the Vandel if it means stopping the enemy. This act highlights a deep-seated sense of duty and sacrifice that remains even when his memories do not. His capture serves as a major motivation for the Beet Warriors to confront Garonewt and a key plot device that tests the heroes' resolve.

Following Garonewt's defeat, Cruss begins to recover his memories. He reveals the true events of the legendary battle against Beltorze, explaining what happened after Beet lost consciousness. This moment is a turning point for Cruss, as he fully regains his identity. He then takes on a new role as a mentor to Beet, instructing him on how to properly master the Crown Shield's abilities. When Beet attempts to return the Saiga to Cruss, Cruss's body is unable to reabsorb it all at once due to the power he lost, so he tells Beet to keep it.

Cruss's key relationships are deeply tied to his past as a Zenon Warrior. His bond with Zenon, the leader of their group, is particularly strong, as Zenon sacrificed himself to protect his team. His relationship with Beet evolves from one of a predecessor and wounded survivor to that of a teacher and student, with Cruss trusting Beet to carry on the legacy of the Crown Shield.

In terms of notable abilities, Cruss is the master of the Crown Shield, a Saiga created from the Divine Power of Water. This Saiga is primarily a defensive tool capable of deflecting nearly any attack. However, it is also versatile, as it can transform into a ball and chain to pummel enemies. Furthermore, the Crown Shield possesses the unique property of being able to cleanse poisons from a body, making it valuable for both offense and support. Even after losing the ability to wield the shield himself, Cruss's knowledge of its techniques allows him to train Beet, proving his experience and skill as a former Zenon Warrior.