Black can wipe the board of creatures all day long, but not being able to remove other problematic permanents like enchantments or artifacts can be a real problem for the color
Sundial, Dawn Tyrant Sundial is an inscrutable walking construct that has traveled the ever-changing landscapes of Muraganda since time immemorial, revered by its followers, the Dawnchaser Pilgrims
In the same scenario, if you have a Detention Sphere and a Jace, Architect of Thought, you would have a difficult decision to make about whether to spend your next turn answering the Zombie or playing a contested planeswalker, whereas with Heros Downfall you can harness a tempo advantage by killing the Lifebane Zombie, untapping, and playing Jace to safely draw cards on an open board
Our final Mindstab Thrull (by Mark Tedin) is probably the most disturbing-looking creature, and honestly feels so fucked-up
but it was a bit stressful on my colored mana sources