Type: Mystic Realm (extradimensional (in that it is outside of Earth's dimension));
    the underworld in the cosmology of Ta-Lo, the realm of the Xian (the Taoist gods formerly worshipped by the Chinese)

Environment: Essentiually Earth-like in some parts, but also Hell-like with various realms of torture and misery

Usual means of access: Physical death of inhabitants of Taoist people and the people of K'un-L'un;

Dominant Lifeforms: Humans Souls/Spirits (Ghosts) and the gods who rule them

Significant inhabitants: Yen-Lo Wang (aka Yama), Yama Kings (see comments); presumably Horse Face, Ox-Head;
    possibly Bianchengwang, Chu Jiang (or Chujiangwang?), Dushiwang, Meng Po, Pingdengwang, Qinguangwang, Song Di (or Songdiwang?), Taishanwang, Wu Chang (or Wuguanwang?), Zhuanlunwang;
    Lord Tuan, Lady Meng (his wife), Pedar, Vikdor, Tomas (soldiers of Tuan);
    Heather Duncan Rand, Wendell Rand-Kai;
    formerly Bowman, Dhaska Khan, Iron Fist (Daniel Rand), Jade, Kou-Hun-Shih-Che, Soulslayer and other inhabitants transformed into demons

Significant Locations: Eighteen levels;
     Bridge of Oblivion, Chamber of Scissors, Chamber of Tongues, Forest of Copper Columns, How-Nai-Ho (River of the Damned), K'u-Ch'u-Ch'iao (aka the Bridge of Pain)

Aliases: Diyu, Fengdu

First Appearance: Deadly Hands of Kung Fu I#19 (December, 1975)

History:
(Thor & Hercules: Encyclopaedia Mythologica: Xian entry/Iron Fist: The Living Weapon#8 (fb) - BTS) - Yen-Lo Wang (aka Yama), the Chinese god of the dead, presided over the eighteen levels of the Diyu (aka Fengdu, Feng-Tu, the underworld associated with the Xian and apparently with K'un-Lun (see comments)).

(Iron Fist: The Living Weapon#8 (fb) - BTS) - Diyu has eighteen levels, each ruled over by one of the Yama Kings.

(Chinese Myth) - On the Bridge of Oblivion (apparently between the 9^th and 10^th levels/courts), Meng Po, the goddess of oblivion, served soup that wiped the memory of a person so he or she could reincarnate into the next life without the burdens of the past life.

(Marvel Premiere#15 (BTS)) - A colony of humanoid aliens crashlanded in their spaceship in a small extradimensional world. The ship's warp-drive engines somehow cause a permanent, oscillating rift between the pocket world and the Earth's dimension, causing the settlement to shift into Earthly space periodically in a site on K'un-L'un Mountain in the Himalayan Range of Tibet. Possibly, the infra-spatial rift between dimensions extends to Feng-Tu where deceased members of K'un-L'un began appearing.

(Deadly Hands of Kung Fu#21 (fb) - BTS) - Lord Tuan, who had been the Yü-Ti (ruler of K'un-Lun), died and became first among the Yama Kings of Feng-Tu, while his son became the new Yü-Ti.

(Marvel Premiere#15 (fb) - BTS / Deadly Hands of Kung Fu#21 (fb) - BTS) - Lord Tuan was saddened when Wendell Rand-K'ai was killed outside of the boundaries of Feng-Tu, resulting in his spirit being seemingly lost to Feng-Tu forever.

(Deadly Hands of Kung Fu#23 (fb)) - Tuan and Lady Meng were surprised when the human Heather Rand, the "terran wife of my son," arrived in Feng-Tu after having been slain by wolves on the bridge to K'un-Lun.

(Deadly Hands of Kung Fu#21 (fb) - BTS) - Dhasha Khan led his forces to invade Feng-Tu, seeking to use it as a base from which to conquer K'un-Lun to gain its power and secrets. The people of Feng-Tu, having long since abandoned the way of the warrior, were unable to stand against Dhasha Khan, and he conquered Feng-Tu.

(Deadly Hands of Kung Fu#23 (fb)) - Khan discovered the spirit of Heather Rand, the mother of Daniel Rand (Iron Fist) and subsequently transformed her into Silver Dragon.

    He also transformed other inhabitants of Feng-Tu into demons to serve his will.

(Deadly Hands of Kung Fu#21 (fb) - BTS) - Dhasha Khan grew tired of being a lord of the dead and schemed to conquer the land of the living. He sent several agents after Jade, who housed the spirit of the Firebird, but she was rescued by Iron Fist.

(Deadly Hands of Kung Fu#21) - Iron Fist fought his way into Feng-Tu, where he met Lord Tuan and the other inhabitants of Feng-Tu, though he saw them in the attire of modern Earth. Seeking to save the Firebird (Jade) from Dhasha-Khan, Tuan pretended to be showing Iron Fist how to defeat Dhasha Khan, guiding him to see Feng-Tu as it really was, the Land of the Dead. In doing so, however, Tuan entranced Iron Fist so that the Bowman could slay him, that he might die in Jade's place.

(Deadly Hands of Kung Fu#22 - BTS) - Iron Fist became one of the shades within Feng-Tu, but he convinced the Bowman and Jade to join him in escaping Feng-Tu.

(Deadly Hands of Kung Fu#23) - On the Bridge of Pain, over the River of the Damned, Iron Fist was confronted by and battled Silver Dragon. She eventually recognized him as her son and refused to slay him, after which she was seemingly destroyed by Dhasha Khan as the Bowman rallied Lord Tuan and his supporters in retaking Feng-Tu.

(Deadly Hands of Kung Fu#24 - BTS) - Iron Fist bridged the gap between life and death, enabling him to confront and defeat Dhasha Khan.

(Iron Fist/Wolverine#4 (fb) - BTS) - Wendell Rand-K'ai eventually ended up in Feng-Tu.

(Iron Fist/Wolverine#4) - Tuan was presumably amongst the inhabitants of Feng-Tu who joined the recently slain Iron Fist in appearing on Earth to bid his friends farewell. However, Wendell and Heather (and the other residents) utilized the ambient magic to restore Iron Fist to life. The residents of Feng-Tu then returned to their home.

(Iron Fist: The Living Weapon#8 (fb) - BTS) - Via the Randall Gate, the Fooh seemingly sent Daniel Rand to Diyu so he could seek out his mother, Heather.

(Iron Fist: The Living Weapon#8) - In the form of a shadowy man wearing a douli (a conical sun hat), Yama (without revealing his own identity) greeted Daniel, telling him it was good to see him again, as all had been to Diyu and all returned there to have their souls cleansed for rebirth. Daniel told him that he did not come there to be reborn, but that he rather came to find someone, and Yama asked him if he was sure about that.

    Daniel specified that he was talking about his mother, and Yama told him that the amount of time one spent there was at the discretion of the Yama and was dependent on the severity of the sin.

     Yama asked about this sinner to help narrow the search of the eighteen realms, asking if she would fit in the First Level: The Chamber of Tongues, where tongues were ripped out for gossip and lies; the Chamber of Scissors, where demons turned ring fingers into necklaces, for those who destroyed the marriages of others; and the Forest of Copper Columns, for arsonists and vandals.

    Daniel interrupted, insisting that his mother was a good and loving woman, and Yama asked then why was she still there, which he confirmed by noting her calling. Hearing screams for a nearby pagoda, Daniel rushed in and was attacked by the soldiers of this hell-realm, whom he swiftly overpowered and/or destroyed.

    Daniel then returned to Yama -- still unaware of his identity -- and told him to take him to his mother's captor, "'this Yama,' or I'll do the same to you."

    Replying, "If you wish to speak to Yama, all you need do is ask...for I am Yama!", he adopted a giant and monstrous wolf-man form and attacked Daniel. Narrowly evading Yama's first strike and realizing he would not be able to dodge him for much longer, Daniel punched his fist through Yama's head, apparently slaying and then skinning him and wearing his hide.