The wrong ones turn into little problems that stack up: slow shuffles, split seams, bent corners, visible wear, and the occasional "Do I need to replace these right now?" panic
on your turn, you can give all opposing Characters -5 to their cost and on playing Kuzan, you can knock out an opposing Character who has zero cost
Unstoppable Slasher This is another in the line of Graveyard Trespasser and Preacher of the Schism of good black three mana midrange card. I suspect Slasher will prove to be the best of these three, since it puts the most pressure on the opponent
Unleash the ultimate force of mechanical madness with the Doc Ock, Evil Inventor Commander Deck a masterpiece of innovation, intellect, and pure villainy
In Modern, building with Concealing Curtains gets a bit trickier, but if you want to avoid the Rakdos trap of losing to Sanctifier en-Vec, I can see Concealing Curtains as a one-drop of choice for an Esper or Sultai Lurrus deck
Card sleeves should make it easier for you to shuffle the deck, not harder