The following Z items can be created by fusing the indicated items:

Attack +6 = Attack +3 and Attack +3
Defense +6 = Defense +3 and Defense +3
Favorite Technique +6 = Favorite Technique +3 and Favorite Technique +3
Finishing move +6 = Finishing Move +3 and Finishing Move +3
Health +6 = Health +3 and Health +3
Ki +6 = Ki +3 and Ki +3
Speed +6 = Speed +3 and Speed +3
Super Finishing Move +6 = Super finishing move +3 and Super