Dimensional Training

Each time you cast a sorcery or an instant , put a "training" counter on this card
{x}, {t} : Copy target spell with converted mana
cost equal to X . Activate this ability only if X are
less or equal to the number of "training" counter
on this card.
Remove 20 "training" counter on this card: All sorceries and instants in your graveyard have Flashback {u}.