User blog comment:Yuii268/A few questions from a beginning player/@comment-37694271-20181214165808

It depends to be honest. From my personal opinion, keep about two of each unit (if it's even usable). You can always check each unit on the wiki and see if they have some potential. I'd recommend saving dupes of units past the Disnomians and especially the newer ones. Or if you'd like, you can upgrade the dupes and use them to evolve the original unit to Omni+. Just my thoughts, if you have older units though, you can choose to keep them for collection or trade them in the at the Imperial Capital administration thing for merit points (those can traded for evolution materials or other items that can be useful!) I hope this helped!