High-Leech Monk

The "Last Gatekeeper" High-Leech Monk ("초후의 문지기" 하이 - 리치 몽크, 'Chohu-ui Munjigi' High-Leech Monk) is an artificial puppet that was created by Po Bidau Gustang to guard the main entrance to the Floor of Death. It will take the souls of people who wish to enter the Floor as a requirement of the spell-protection system. Gustang has verified that the last gatekeeper is a puppet that belongs to him, stating:

"I was wondering who destroyed my puppet.. It looks like a very pretty bug has wandered in here"

- Po Bidau Gustang to White.

Appearance and Personality
The High-Leech Monk resembles a traditional monk with wooden-looking skin, a shaven head, elongated earlobes, piercing red concentric eyes, and a pink Urna in the centre of his forehead. It wears a navy blue garb fastened round the waist by a blue sash and a thick golden banglet around his neck. High Leech Monk also was able to levitate barefoot.

History
The High-Leech Monk's primary mission is to prevent those from entering and exiting from the Floor of Death without offering their souls as payment. It prevented Twenty-Fifth Baam and David Hockney from entering. The High-Leech Monk was eventually destroyed by White when it tried to stop him and Karaka from leaving with the souls absorbed.

Powers and Abilities
"With that level of technical expertise, whoever made that thing has some serious skills."

- Karaka to White talking about the High Leech Monk The High-Leech Monk was equipped with advanced technologies that were built by Po Bidau Gustang, the father of science and medicine  in the Tower.
 * X-Ray Vision and Living Soul Detection : It is capable of seeing the souls of the living, enabling it to see through solid objects; so it's eyes cannot be deceived.
 * Shinheuh control: The High Leech Monk has control over the Soul Devourers.
 * Shinshoo Bamboo Spears: The High Leech Monk is able to create many Bamboo Spears to fight against its enemies. The Bamboo Spears are shinshoo baangs with the shinshoo quality of bamboo. It fought Twenty-Fifth Baam and David Hockney with dozens of bamboo spears. According to Hockney, one has to aim at the empty center of the bamboo spear to destroy it. When facing against high rankers (like in case of Karaka and White), The High-Leech Monk will show an extreme show of force of power to control more than hundreds of bamboo spears.
 * High Rankers detection: It seems that the High-Leech Monk also has technology to detect dangerous high rankers presence as shown when it was fully ready to fight and prevent Karaka and White from leaving the Floor of Death even before the high rankers were in sight.

Notes and Trivia

 * The final gatekeeper is an artificial puppet that was created by Po Bidau Gustang.
 * Despite being the one who protects the entrance to the Floor, he appears to defer to certain 43rd Floor inhabitants of great power, such as Garam Zahard.
 * The final gatekeeper is based on the Four Heavenly Kings in Buddhist temples. SIU likes them, he likes going to religious buildings because it's good for introspection.