Sage of the Beyond

Flying
Spells you cast from anywhere other than your hand cost {2} less to cast.
Foretell {4}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Saw It Coming

Counter target spell.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Doomskar

Destroy all creatures.
Foretell {1}{W}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Cosmos Charger

Flash
Flying
Foretelling cards from your hand costs {1} less and can be done on any player's turn.
Foretell {2}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Niko Defies Destiny

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — You gain 2 life for each foretold card you own in exile.
II — Add {W}{U}. Spend this mana only to foretell cards or cast spells that have foretell.
III — Return target card with foretell from your graveyard to your hand.

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.