here are my thoughts about the events:

1. Treasure of the Sage
Always a good event for both f2p and paying players, the only thing i would want different is the ninjas you can buy from there we only have 1 event ninja in this time. Put in more Event only ninjas like Sailor Sakura, Iruka, cursed Hidan, Hanzo (you can even limit those rare ninjas like cursed Hidan and Hanzo to 10% rebate). I just dont see anyone buying Pains or Orochimaru KT at those prices.

2. Mission General Mobilization
Also a good event for both kind of players and good redeem rewards.

3. Arena Mission
Free Stuff for everyone is good, an incentive to play arena at this time may look a bit strange bc all of the outrage but people forget you c*so do this in Trainings Mode. Im ok with it

All around 3 good events a bit less than the last few weeks but nothing really bad in it either.