Wizards of the Coast brought about the Commander power brackets which take many of these rules into account and help players get good games
Card Advantage When a players able to draw multiple cards when casting just one spell or within one activation of an ability, that opens the door to increased card advantage
The rules on Battles were written in such a way as to enable any kind of spell being on the other side
[20] If you have any misprints and youre curious about their value, post what youve got over on the Pokmon Misprint subreddit
So if I make my commander Captain America, First Avenger (a red-white-blue creature), I cannot use any green or black cards while building that deck
Hes not looting away cards, which unfortunately doesnt do much for graveyard-based decks like Jace did, but the enchantment he transforms into is arguably stronger than Jaces Planeswalker side