Some errors are very common, but certain types of error cards can be very valuable due to their uniqueness and scarcity
Inflict 800 damage to your opponent for each sent card, also for the rest of the turn, reduce all effect damage your opponent would take from non-Fiend monster effects to 0
commanders like Kess, Dissidant Mage and flashback cards (Past in Flames) get hosed but other graveyard strategies such as Meren of Clan Nel Toth, dredge cards (Life from the Loam), or staple reanimation spells (Animate Dead) are unaffected
Creatures that impose Role tokens as a downside can also be strategically managed by replacing a negative Role with a more advantageous one
Drogskol Reaver Seven mana is a lot to pay for a 3/5 with double strike, but what about a flying, lifelink, double-striking creature thatll draw you at least two cards every turn when it deals damage