They need a system that knows how much tomes you've gotten so far, and when you hit leave, it prompts, "are you sure you want to leave and lose the myth you have acquired so far?" Sense this could screw up Brayflox Myth runs, They would need to also make adjustments to the vote abandon system. Like if its a premade, then vote abandon is available from the get go or they could make the leave penalty null if its 100% premade group. That way you can leave without losing your reward in a premade group. They could also make this effect anyone that disconnects, and/or is afk and gets kicked. Obviously it would suck, if you were the unfortunate person that loses connection after the second boss and lose your 50 myth. But that isn't going to be a regular thing, and I think it would be worth it, to stop people abusing DF groups.