Combo-control decks are great for players who enjoy the controlling strategy but dont want to spend their evenings tucking Teferi 50 times, or for players who like the idea of combo decks but dont care for the all-or-nothing playstyle that engines can result in
The other mentions are basically any of the Gisa or Geralf iterations, all of which are easy includes in any deck that cares about having the best Zombies in Commander in it, because they make a lot of Zombies and have some excellent synergies
Though the decks this belongs in might be narrow, this spinx is absolutely solid
Still, some version of this effect could be a cool enabler, and I would love to see this as a combo piece in a Laboratory Maniac deck
An instant speed kill spell is mighty, and the treasure helps mitigate the cost, so at first it's hard to see why this might be