Card
Basalt Monolith
Artifact · MV 3.0
Oracle text
This artifact doesn't untap during your untap step. {T}: Add {C}{C}{C}. {3}: Untap this artifact.
Rulings
2020-08-07 · Basalt Monolith's last ability can untap it as often as you can pay for it. If you believe you've found a way to generate an unbounded amount of mana with it, you're probably right.