Fourteen solutions need to be partially amended before entry into the grid in a consistent manner by undergoing either a hundredfold increase or a hundredfold decrease. Resulting grid entries are not real words. Definitions in these clues refer to the original solution, while the wordplay and numbers are for the amended form.
1a Female fairy I see eating seaweed, afraid to go out (12) assume it ends ...phobic?
18d Book service for kind of fuel (7) B??????
21a Argentinian music-maker's fight over bulb (9) looks like LEUDONION ??