Tidal Influence

Enchantment, 2U (3)
Cast Tidal Influence only if no permanents named Tidal Influence are on the battlefield.
Tidal Influence enters the battlefield with a tide counter on it.
At the beginning of your upkeep, put a tide counter on Tidal Influence.
As long as there is exactly one tide counter on Tidal Influence, all blue creatures get -2/-0.
As long as there are exactly three tide counters on Tidal Influence, all blue creatures get +2/+0.
Whenever there are four tide counters on Tidal Influence, remove all tide counters from it.¹
Illus. Tom Wänerstrand

Gatherer Card Rulings [Nov 2009]

• 10/4/2004: As soon as the number of counters on this card changes, so does the power of blue creatures.

Format Legality	Legal in Vintage, Legacy Banned in Extended, Standard
Printings (1/1)	Fallen Empires (Uncommon)