Is lazyness a killer? If so, in how far is it a killer, a quality that harms?

How does it arises, when arising? How does it vanish?

[Note that this isn't given/asked for trade, exchange, stakes or other layziness supporting means but for liberation]
Once the Exalted One spoke to the Venerable Maha-Moggallana thus: "Are you drowsy, Moggallana? Are you drowsy, Moggallana?" — "Yes, venerable sir."

(1) "Well then, Moggallana, at whatever thought torpor has befallen you, to that thought you should not give attention, you should not dwell on it frequently. Then it is possible that, by so doing, torpor will disappear......................

AN7.58

https://www.accesstoinsight.org/lib/authors/nyanaponika/wheel026.html