According to Wizards, you have a 1 in 3 chance of opening a nonfoil FCA in Play Boosters, with a 63.25% for that card to be uncommon, 29.75% to be rare, and 7% to be foil
Whereas Urza's journey in The Brothers' War ends with him becoming a planeswalker, Mishra has a more ignominious fate, becoming a sinister Phyrexian
Marrow-Gnawer + Karumonix, the Rat King Basically a rat version of Krenko, Mob Boss, my only issue with Marrow-Gnawer as a beginner commander is that the card itself is rather expensive
Lessons don't currently see a ton of play in other competitive formats, but there are a few popular Commanders for the archetype
Brisela, Voice of Nightmares Brisela is a metal MTG card through and through
to 15 Dec