An effect that gives flashback to an instant or sorcery card in your graveyard stops applying once that card has left the stack. The card won’t have flashback while exiled and can’t be the target of Runic Repetition (unless it naturally has flashback).
22-09-2011
wotc
A card that’s exiled face down doesn’t have any characteristics or abilities, so it can’t be the target of Runic Repetition.
22-09-2011
wotc
The card could have been exiled for any reason, not just because it was cast using flashback.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.