so does Ladder Slasher sometimes resets complety?
if yes?
when and how long does it take between 2 restarts?

The Ladder is reset when someone playing the Alchemist class passes, there is no set amount of time, it all depends on who passes/ when they pass.

Yes, it does. Whenever, someone pass's the MQ with the last chart in game ( Alchemist )

It will reset.

No one knows how long it will take.

Also if someone resets the ladder on Softcore, Hardcore is still the same, and the other way around.

thanks for responses!