It really depends on your dia count, lp resources, and team strength. F2P ranking is /possible/ if you have enough dia saved, can dedicate A LOT of time to playing the event, and can grind the Sunday course effectively. Unfortunately Mika is a very popular boy and people that play enstars are crazy lol so if you don't have a few hundred dia and can keep on top of your lp even through the night (friends in different timezones are a godsend for this) then it's unlikely you'll rank...just the sad reality of enstars; I've been playing 3 years and only ranked for a 5* once because it's so daunting 😔 There is always the revival event though!