Zaun, City of Iron and Glass

This card enters the battlefield tapped.
When this card enters the battlefield, put a Gold artifact token under your control.
{1}, {t}: Add {u}{u}, {u}{b} or {b}{b} to your mana
pool.
A large, undercity district, lying in the deep canyons
and valleys threading Piltover. Inventors who find
the restrictions placed upon them in the city above
find their dangerous researches welcomed in Zaun.