As an instant whose rules text spells out its effect, Wrong Turn is so flexible, even for just manipulating combat
In addition, both come with a form of evasion (Islandwalk and Flying) which is very important (and most useful on Thada Adel, Acquisitor)
These cards demonstrate blacks strong suite of graveyard control
Zell will also be a valid Commander pick in his own right, too, though only giving access to red cards will limit his potential compared to other options
In that deck, Bloodghast can enable absurd amounts of card draw and ramp if it's combined with my commander and a way to untap her like Thornbite Staff
Passive draw engines, opponent-taxing hatebears, and the format's most punishing "pay or I draw" effects card advantage wins games, and these are the pieces that generate it across every color combination