Watcher of the Spheres
Creature — Bird Wizard
Flying
Creature spells with [[ keyword: "flying" ]] you cast cost 
less to cast.
Whenever another creature you control with [[ keyword: "flying" ]] enters, this creature gets +1/+1 until end of turn.
G-host Lee
Core Set 2021 (M21)
• #227Rulings
The cost reduction applies only to generic mana in the cost of creature spells with flying you cast. For example, if you cast a second Watcher of the Spheres, its cost won't be reduced below {W}{U}.
(wotc • 2020-06-23)
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions (such as that of Watcher of the Spheres). The mana value of the spell remains unchanged, no matter what the total cost to cast it was.
(wotc • 2020-06-23)
A creature spell that doesn't have flying won't cost less even if an effect will cause the creature to have flying once on the battlefield. This is also true if the creature spell itself has an ability that gives it flying once on the battlefield under certain conditions, even if those conditions are true.
(wotc • 2020-06-23)
Price History (USD)
Loading...
Price History (EUR)
Loading...
Rulings
The cost reduction applies only to generic mana in the cost of creature spells with flying you cast. For example, if you cast a second Watcher of the Spheres, its cost won't be reduced below {W}{U}.
(wotc • 2020-06-23)
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions (such as that of Watcher of the Spheres). The mana value of the spell remains unchanged, no matter what the total cost to cast it was.
(wotc • 2020-06-23)
A creature spell that doesn't have flying won't cost less even if an effect will cause the creature to have flying once on the battlefield. This is also true if the creature spell itself has an ability that gives it flying once on the battlefield under certain conditions, even if those conditions are true.
(wotc • 2020-06-23)