It's pretty dejecting to see those threads when you play since 14 months, you invest 2000+ coupons every time this event appear and you never got a single ninja from those packs.

They should add a hidden counter to prevent people from getting dupes when other people that spent 20 times as them still has to get him. Something like after the first time you got him you have to buy a very minimum of 5000 packs (trough the months of course) to unlock again the chance to get him. It's unfair towards people like me.