The cost reduction applies to minion cards, they are also played by the Methuselah.
101443
Powerbase: Tshwane
Master: unique location. Requires a ready Laibon.
Lock this location to reduce the cost of a card you play by 1 pool (this location is not locked if that card is canceled as it is played). Any Laibon may steal this location for his or her controller as a Ⓓ action.
Rulings
Can be locked to reduce the cost at any point before resolution, from when the action is announced to just before the cost is paid. If it is used when announcing an action, and the action is cancelled as played (e.g. Direct Intervention), it is not locked.
Can reduce the cost of an action card even if it is not played as an action (e.g. a weapon played with Concealed Weapon or an Ally with Piper).
Allows to play a card that could otherwise not be afforded, in which case, it must be locked when the action is announced.
The action provided by this card is considered to be an action requiring the listed clan/sect/capacity/title (e.g. the action provided by Open War is considered an action that requires an Anarch, the action provided by The Gate of Acheron is considered an action that requires Hecata).