Since Nexus of Fate shuffles back into your library once it goes to your graveyard, Nexus of Fate decks won by drawing their entire deck, getting some finisher on the battlefield, and then repeatedly casting Nexus of Fate to take infinite turns
Throw something scary away and your opponent will immediately be worrying about what you are keeping
Thats clues, treasures, food she turns the lot into mana
On the other hand, getting a third turn Durnan and then swinging with a fourth turn pre-combat Agent isn't that bad either, right
The mythic rare slot is 1/8 (or 0.125) of a slot because rares are 7/8 (see above)
Equip Ghyrson with a Basilisk Collar (or a Gorgon's Head, Gorgon Flail, or Quietus Spike) to grant him Deathtouch, and suddenly those plinks will now kill most creatures - the kind of upgrade that makes junk like a Rod of Ruin look perfectly playable