For example, if Warrior is the chosen creature type and you control Bramblewood Paragon (a creature with "Each other Warrior creature you control enters with an additional +1/+1 counter on it."), a Runeclaw Bear would enter with an additional +1/+1 counter
The Mardu Marchesa assumes youll be attacking with all your creatures each turn, leaving yourself open to losing the monarch on the return swing
You could add black to your deck with Clara Oswald or Vislor Turlough, though, canonically, Donna or Rose Noble would be the way to go
Feed the Swarm handles the permanents your creature removal cant touch, and Damnation is the reset when a go-wide deck gets ahead of you
Accessories not included.
For example, an alpha and beta Black Lotus is going to be worth a lot more than an unlimited and revised Black Lotus, just because it was from the rarer, harder-to-come by initial release