Angel Grove

At the beginning of your upkeep, if you control
three or more artifacts, you gain 1 life.
{t}: Add {1} to your mana pool.
{4}, {t}, Sacrifice Inventors' Fair: Search your
library for an artifact card, reveal it, put it into
your hand, then shuffle your library. Activate
this ability only if you control three or more
artifacts.
—
Inventor's Fair