RNG Wheels has its own good benefits also, like for example, the Lucky Star Wheel, if you're targeting some power-up items in the redeem shop of that event then the wheel is good to spend, while having stars to redeems some power-up items, you will also have a chance to hit the jackpot ninja .. But on the other hand, if you targets the Jackpot Ninja then that's the time that you will destroy your life as you say .. RNG is not your best buddy to rely on, so it is much better to keep and save up your coupons and go for the events where you can piece some frags for your liked ninja ..