There is no longer any rank or killing * onus, the perpent is there for you and your team mates to attack and i think you can attack in teams and you have 2 attempts instead of 3, plus there is no longer those annoying hostile ninjas after first attack. i did it twice on 2 accs and got 40 coupons each time so 80 total, but i did it alone and snake heals like sailor sakura`s passive it sems so i barely did any dmg so mabye when doing it in teams you can get more coupons but im not sure about it, maybe 40 per try is the cap.