High buyer intent (group members are all prospective customers)
Being able to bring back a creature from your graveyard and back to your hand can be very helpful in drawn-out games, while the lifegain can keep you healthy in the face of your opponents
Mana Curve The mana curve seems more middle-range centered that usual, with many drops on 4-5 drop positions, a spike at 4 drops and an absence of 8+ drops
Each card has a different effect depending on the character, and most support cards are discarded once played
Thankfully, Wilhelt is in the colours of Black and Blue (Dimir), and with that, we have access to tutors (cards that let you search for other cards in your library) and counterspells (cards that prevent other cards from being cast) in Magic: The Gathering respectively
Basically, they are cards that are otherwise typical creature cards, but some condition allows you to flip them over so that they become a new card