@kaluma I opened 2 Liliana of the Veil in my chests the other week when I got second in the challenge and brewed up a Bgw “Pox” style deck (doesn’t haven’t any actual Pox or Smallpox) with DRS, Bob, Necro, Chains, Trophy, Wasteland, Stony, Null Rod, etc., haven’t actually played any games with it yet though.
I'm not 100% on this. But I think if chains was really worth using Spirit of the labyrinth would see more play in hate bear lists.
Almost all hatebears decks do play Spirit of the Labyrinth these days. Even quite a few Eldrazi lists run it (competing with Glowrider and Sphere of Resistance in the flex spot that used to be Thorn of Amethyst).
Chains of Mephistopheles might be used to great effect with decks that mainly use "take the card into your hand" type of cards. Necropotence, black tutors and Dark Confidant are the big ones that come to mind. There are also blue cards like DTT, Fact or Fiction, and Gifts Ungiven that do this. There might be a new deck that might be able to use these ideas functionally, but I'm not sure if it can be well-rounded enough to handle Eldrazi or Shops lists as well, or not be suboptimal.
The real question is not how creature oriented control (aka hatebears, a name I do not like btw...) beat PO decks. Since the meta is now Bazaar, Workshop and Blue (PO or non PO does not matter, they all need to draw plenty of cards to win) it seems very hard to fight these decks with classical strategies. And with this I mean 4x Hatebear A, 4x Hatebear B, 3x Stony, 4x Removal C, ...
My judgement is that right card is Hurkyl's Recall and not Stony Silence. You just run your own power and acceleration and bust out the most powerful permanent based creature disruption and back it up with a healthy combination of Mental Misteps, Mindbreak Traps, REB, ... You also run tutors and deck manipulation (top, dack, dt, ...).
A Hurkyl's Recall plan will also work well with a singleton Chalice of the Void + Sphere effects against PO. Workshop tend to take a lot of damage if their explosive start was based on Mana Crypt and Ancient Tombs. Also note that after a mass bounce, your Mindbreak Trap is most likely going to be active, even against Workshop.
I was on a long break, just returned like a couple weeks ago, but the Oath of Ghouls 5C Humans deck from 2015-2016 was the first time I switched from a classical way of building aggro control based on mana denial (wastelands, stony) to a more soft lock approach without wastelands and stony (which is sometimes in the SB at best), but with my own broken stuff basically. Losing a Thalia is actually kinda the plan, because all you want is time to set up a more stronger position with Kambal and spells that disrupt the PO.
All this being said, with the recent emergence of Bazaar Survival, not even Hurkyl's Recall seems like a plan anymore. And do not forget Oath and Bazaar Dredge lurking around. So yea... hard times