On an opponents turn, you can cast it for its alternate cost by exiling a blue card from your hand instead of paying mana
Is the character truly undefeated
Since it has the changeling ability, its technically a Wraith, and it will unlock cards from all five colors if you want to go beyond mono-black
In fact, judging by whats happened to past Universes Beyond cards, Rick may only be worth a few dollars following their reprint
Play mode is your typical competitive-but-not-ranked fare, where you can be placed against an opponent with any ranking, and can test your deck in a more realistic scenario against an actual human
The payoff of this meld pair, doesn't win the game on the spot, and I'd stress that to your Bracket 3 playgroup because while this deck puts together powerful cards, it is not optimized to be unbeatable, and more focused on a huge play with some Golgari death and graveyard interaction molded in