I would say damage > time since that's what the guy wants to base the record off.

And yes 12 damage in 5000 frames would be better than 13 damage in 59 since this record is based on the lowest amount of damage done. And it shouldn't be hard to explain to newer players if they understand that definitively damage > time. And I also think it would be a cool world record since I wanna see what moves people would do.