The discard is the official rule from the rulebook:
Redemption® Rulebook > Diagram of a Turn > Preparation Phase > Artifact Activation
Some artifacts, covenants, or curses have a limited number of times you can use them. When these come to an end, you must discard them immediately. Once such an artifact, covenant, or curse is activated, it must be counted as having been used. This is true even if other events duplicate the effect of the artifac, covenant, or curse during the turn.