Veronica, Dissident Scribe

Menace
Whenever Veronica attacks, you may discard a card. If you do, draw a card.
Whenever you discard one or more nonland cards for the first time each turn, create a Junk token. (It's an artifact with "{T}, Sacrifice this token: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")