User blog comment:Crimson Storm Mich/Future Units Preview v2/@comment-28071192-20160528060003/@comment-26944381-20160602013238

Well, Alim said that the units don't need to be 7* to evolve into OE, but they never specified how low they have to be so a 5* can enter on the range to get OE, which will allow old RS unit to get OE (still waiting for my Rigness 7*/OE btw...). A good point would be that they are free units and unless they are like Mifune (not necessarily nuker but good enough on their own category to enter on Mifunes level (thing that we know they aren't)), it will be really hard for them to get an OE, unless Alim decide to give them one by x or y reason.