Illusion is a special technique utilized by several characters.
Shantza sends red beams out of his cheeks creating a red dome around his opponents. Inside the dome he creates illusions to try and trick his opponents.
According to Dragon Ball Z: Kakarot, during the training in preparation for the Saiyan attack, Piccolo did not actually destroy the moon, but instead created an illusion of it's destruction in order to have Gohan revert from his Great Ape form.
In the Tournament of Power, Dercori utilized illusions via her Mystic Talismans in her battle with Master Roshi, with 129 possible illusions in her arsenal. Shantza used his illusion technique to create illusions of the erased fighters against Universe 7.