Mana Tithe

Counter target spell unless its controller pays {1}.

Counterspell

Migratory Route

Create four 1/1 white Bird creature tokens with flying.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Island

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Watcher of the Spheres

Flying
Creature spells with flying you cast cost {1} less to cast.
Whenever another creature you control with flying enters, this creature gets +1/+1 until end of turn.

Aegis Sculptor

Flying
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
At the beginning of your upkeep, you may exile two cards from your graveyard. If you do, put a +1/+1 counter on this creature.

Steel-Plume Marshal

Flying
Whenever this creature attacks, other attacking creatures you control with flying get +2/+2 until end of turn.

Harrier Strix

Flying
When this creature enters, tap target permanent.
{2}{U}: Draw a card, then discard a card.

Plains

Healer's Hawk

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Detention Vortex

Enchant nonland permanent
Enchanted permanent can't attack or block, and its activated abilities can't be activated.
{3}: Destroy this Aura. Only your opponents may activate this ability and only as a sorcery.