can't merge 2 Gear2 Monkey D Luffy

I have 2 Gear2 Luffy but can't seem to merge them. The status for both if I try to power them up is always "In Use". Anyone can help? Thank's

It could be that you are still using gear2 as a captain in the other crews. The one you don't use. Just put him out of all the 6 crews and then it should be possible.

Tried your suggestion. Didnt work. The problem is not with my higher level Gear2 Luffy, but with the lesser one that is always in "In Use" status, although it is never on the team. Could it be a bug? Any suggestion pls

I don't know my last idea would be to clear all crews and put someone else like zoro as captain in all needed slots and try again. Otherwise i have no idea what you can do. sorry

It's fixed, thanks to Mystogan. I rechecked. The gear2 luffy somehow listed as captain on team 2 - 6. After I replaced all of them, no problem.