Dredge on Past Deeds

This spell cost {5} less if any opponent and you
has five or more cards into their graveyard.
Until your next turn, cards in all graveyards has
Dredge X where X is that card converted mana
cost.
Target opponent may return a card from your
graveyard to their hand paying its Dredge cost.
"I will show you the reality, then you can judge"