Now i'm interested to see an online game that instead of Universal Stamina/Energy system, it has Individual Boredom/Fatigue system. A character/unit will accumulate Boredom/Fatigue each time they clear a stage, and will suffer debilitating penalties based on how much it had accumulated. This of course would kinda invalidates auto-play-grinding, tho it's not like i'am a fan of game that relies too much grindfest to prolong game time anyway.
@NightSide, there's some event gacha that came with a "failsafe", that is, if you didn't get any UR/5* etc for (high) numbers of pulls, you are guaranteed to get one on your next pull. The value of the failsafe-trigger will then reset everytime you pull a jackpot.
But yeah tho in his case, he was being too "optimistic" with the worst-case scenario, lol.