see: Dao (sword)
Dan Tien Dao is a weapon used by Shujinko in Mortal Kombat: Deception and Mortal Kombat: Armageddon. Technically the Quadspade is a Dan Tien Dao as well. When Shujinko executes any of his Mortal Kombat: Deception Fatalities, he will use two Dan Tien Daos.
Quadspade wielded by Liu Kang
Weapon Concepts for MK: Deception