The Deck is focused around Trespasser's Curse, and it's various synergies. Over the years, different interactions have revealed to help come up with new tech surrounding this card. Typically, with TC in play you have Forbidden Orchard or Hunted Phantasm to burn/drain your opponents over the course of the game.
For the last 8 years (since Amonket's release), the deck has gotten better and better, with more and more cards supporting the strategy. Overall, I've noticed that, if I can get 2 TC's on the battlefield, my win% skyrockets.
Normally, your strategy is to add creatures to your opponent's board, but to kill everything as much as possible or reduced damage so you don't die. It's inherently a bad strategy, because you are arming your opponent with more tools to kill you as well. I think that's why people often write it off. It still works as a strategy, but I've been trying to develop a more effective strategy. Not sure if I'm there yet, but getting closer. My personal win% in competitive play is about 30%, and often lose to reanimator or combo strats. Against creature strats I usually win closer to 50-60% of the time, and it usually functions best as a control deck. There is the Dagger Burn version that gained popularity through Saffron Olive's against the odds videos, and it very much did alright.
I have been playtesting a similar version to the above list on Arena with some success. In this version, you want your opponent's creatures to stick around as much as possible. The reason being, is that the Phasing of Zhalfir is an insane bomb, which also tempers the damage that your opponent is trying to achieve with their own board. My arena version does focus on having Amulet of Safekeeping to reduce token damage, but it feels like a bit of a dead card on occasion. Also, in my previous modern decks, I almost always restrict Hunted Phantasm to 2 copies in the main. This is because you usually don't want to just play this creature until you are set with a curse on the field.
In this version, you use Gadwick's First Duel to make their better creatures into useless 1/1's, or Unable to Scream. Gadwick's was a deliberate choice because it produces more enchantments for Estrid's Invocation, scrys, and potentially copies the 4 of Commune with Spirits. Being sorcery speed, 2 mana, and not utilizing the last mode very often are maybe reasons I would push for more Screams. You do this just to keep the board full for a bigger Phasing of Zhalfir. This brings me to the biggest weakness of Trespasser's Curse, and especially this build.
The deck doesn't function without Curse, at least not well. You want Curse on turn 2, or to be able to get multiple TC's going. This is why the deck needs tutors or draw effects. (I'm workshopping another version with Mausoleum Secrets or Profane Tutor for this reason). Other versions have access to a host of creatures like Bloodseeker or Suture Priest or Blood Artist, etc. Those are very easy to kill, and not super reliable. In this version, a creature-based TC effect is especially less effective, because the end-goal is to board wipe with Phasing of Zhalfir, and they will not trigger with the new 2/2 horror's that enter after. Warlock Class is nice in a version that kills the tokens right away (via Illness in the Ranks), but not that effective here. We need more Trespasser's Curse. So in comes Gonti's Machinations. It's a 1 mana card that can drain for 3. Often you are losing the life to the tokens you gave your opponent, so in essence, it's a similar effect. Between 1 curse and 1 gonti's, you are often draining for a total of 8 damage. Pretty much halfway there?
You can see that by having a threshold of these cards will quickly bring your opponent to zero, all the while gaining that life to keep yourself alive long enough to do so.