I've decided to include Dai Viet (Vietnam) in the mix as a playable civ. Though Vietnam is literally in between the sphere of Southeast Asia and East Asia, exhibiting influence from both sides of the spectrum, its major interactions as a regional power occurred with China and the Mongols. Vietnam is
not a mere extension of Chinese culture, but developed in response (and resistance) to Chinese domination and successfully repulsed both repeated Chinese and Mongol invasions. The leaders of Dai Viet will be Ly Thai To in the first version and Trung Trac in the second version. Viet special units will include the Au-Lac Crossbowman, the Viet Guerilla, the War Elephant, and the War Canoe.
Anyways, a complete list of the "UUs" and leaders that each civ will have:
China
Leaders: Ying Zheng -Or- Wu Zetian
UUs: War Chariot, Zhuge-Nu, Castle Ship, War Tiger Paddleship
Japan
Leaders: Suiko -Or- Minamoto Yoritomo
UUs: Heian Horse Archer, Wa-ko, Sohei, Ashigaru Arquebusier
Korea
Leaders: Wang Kon -Or- Sejong
UUs: Hwarang, Koryo Horse Archer, Iybyon, Kobukson, Hwach'a
Mongols
Leaders: Genghis Khan -Or- Kublai Khan
UUs: Raider, Mongol Light Cavalry, Keshik, Tibetan Auxilary
Tibet
Leaders: Ngawang Gyatso -Or- Songtsen Gampo
UUs: Himalayan Warrior, Tibetan Light Cavalry, Khampa Horseman, Khampa Archer
Dai Viet
Leaders: Trung Trac -Or- Ly Thai To
UUs: Au-Lac Crossbowman, Viet Guerilla, War Elephant, War Canoe