Four Witches Technique (四妖拳,Shiyōken, lit. "Four Supernatural Fists") is a technique invented by the Three-Eyed People.
The user temporarily grows two extra arms from the back, seemingly under the shoulder blades. This allows the user to attack with twice the intensity that they would normally be capable of.
Tien uses the Four Witches Technique during his fight with Goku in the 22nd World Martial Arts Tournament. Although it initially proves effective, Goku uses King Chappa's Eight Arms Technique to counter it. When Goku grabs Tien's legs and held them up, causing Tien great pain, Tien attempted to use his extra arms to suffocate Goku, but stopped because of the pain, and his extra arms disappeared.
Upon becoming a farmer after the defeat of Majin Buu, Tien uses the Four Witches Technique in conjunction with the Multi-Form for harvesting crops.