The Visitor Event Guide/Discussion.

I used a STR core on all 4 equips, then used 1 LUK on each, then 1 more LUK on Gloves and Hat (ran out of medals) and on the 3rd slot both the gloves and hat transformed into the lucky versions(on a Lv.78 CB) even though I used STR first. Very stange.

Well, we only have confirmation through the ones that upgrade after only two slots. The more likely scenario is that it checks for the majority cell used just prior to applying the cell that is on the slot where it transforms. Gonna take more time for people to have any confirmation on the 12 slot transforming ones.