The Main Deck Negators are Endymion, the Mighty Master of Magic (S/T card or effect, SOPT), Mythical Beast Jackal King (monster effect, SOPT), Reflection of Endymion (bounce when SS by Selene), and, in Draw Endymion, Magician's Right hand (first Spell Card/effect each turn)
This effect doesn't target, and if you want to return a card from the hand back into the Deck, its chosen randomly
Spending a bunch of time and resources stacking +1/+1 counters on creatures can prove fruitless when a single timely board wipe undoes all that work
Paradoxical Outcome The best-case scenario for Paradoxical Outcome is to bounce your board in response to a board wipe, saving your stuff while drawing cards in the process
Jace and Reprint Equity Back in November, we discussed the future of Masters sets and how Wizards was slowly but surely running out of expensive cards to reprint (probably better know as reprint equity)