Tony Stark, Master Inventor

Whenever you draw your second card each turn, create a tapped Invention token (a colorless artifact with 'Discard a card, {t}: Surveil 1')

Whenever an artifact is put into your graveyard from your library, you may draw a card. This ability triggers only once per turn.

Sacrifice X untapped Inventions: the next Stark artifact you cast this turn costs {x} less to cast. Activate only once per turn.