Siphon Gate

When Siphon Gate enters the battlefield, each
player puts a siphon counter on a land that
player controls.
Tap this land to add one colorless mana to your
mana pool.
Tap this land to add one mana to your mana
pool, of any type that target land with a siphon
counter can produce. Target land doesn't untap
during its controller's next untap step.