UAC Sentry Bot

Whenever you cast an Aura or Equipment spell, put a +1/+1 counter on UAC Sentry Bot.

When the Sentry Bot dies, create X Junk
tokens where X is the number of +1/+1
counters on it. (They're artifacts with "{t}, Sacrifice this artifact: Exile the top card of
your library. You may play that card this turn. Activate only as a sorcery.")