You must play on hardest difficulty level - Legendary. Get to act 3 Orient and find Changhan tow. From that one get to Quinba bamboo forest. Stood on main road and you find out general who gave you quest A General in Repose. After that go to the cave southeast and on the other side you will find hidden location - Shrine of Zhong Kui. Here you can find out Dragon Liche. Bring high resistance against poison + good is pet and + damage against Undead.