Glorious Protector

• WOTC Official Reminder Textofficial rules
  Flash — You may cast this spell any time you could cast an instant.
• WOTC Official Reminder Textofficial rules
  Foretell — Foretell [cost] (During your turn, you may pay and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

• WWizards of the Coast2021-02-05
  Official Ruling
  If you're casting a foretold card from exile for its foretell cost, you can't choose to cast it for any other alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, those must be paid to cast the spell.
• WWizards of the Coast2021-02-05
  Official Ruling
  If Glorious Protector leaves the battlefield before its triggered ability resolves, no creatures will be exiled.
• WWizards of the Coast2021-02-05
  Official Ruling
  Casting a foretold card from exile follows the timing rules for that card. If you foretell an instant card, you can cast it as soon as the next player's turn. In most cases, if you foretell a card that isn't an instant (or doesn't have flash), you'll have to wait until your next turn to cast it.
• WWizards of the Coast2021-02-05
  Official Ruling
  Auras attached to any exiled permanents will be put into their owners' graveyards. Any Equipment will become unattached and remain on the battlefield. Any counters on the exiled permanents will cease to exist. When the cards return to the battlefield, they will be new objects with no connection to the cards that were exiled.
• WWizards of the Coast2021-02-05
  Official Ruling
  If a token is exiled this way, it will cease to exist and won't return to the battlefield.
• WWizards of the Coast2021-02-05
  Official Ruling
  Glorious Protector's enters-the-battlefield ability doesn't target any creatures. You choose which non-Angel creatures to exile, if any, as that ability resolves.
• WWizards of the Coast2021-02-05
  Official Ruling
  Because exiling a card with foretell from your hand is a special action, you can do so any time you have priority during your turn, including in response to spells and abilities. Once you announce you're taking the action, no other player can respond by trying to remove the card from your hand.

Rulings via Scryfall