Well I don't play a whole lot of Unlimited anymore but I've heard of Porydonk which consists of
Porygon2 GE and using its PokePower to continually reuse
Seeker. With
Broken Time Space you could just pick up Porygon2 for Seeker and lay him back down, while your opponent has to remove a benched Pokemon each time. You can use
VS Seeker to get more Seekers back, too. For the last Pokemon on your opponent's field you can use Broken Time Space to lay down Drifloon and then
Drifblim and attach a
Boost and then Switch out to it to Take Away the last Pokemon. You would use the basic Unlimited staples to draw through your deck like Professor Oak, Erika, etc.
However, like many Unlimited decks, it's susceptible to T1 locks. A T1
Dark Vileplume via Broken Time Space can hurt but fortunately you can use
Uxie rather efficiently in place of other trainers because you can Download Seekers with one of your other Porygons (which doesn't count as "playing" them) to reuse them. Most notably a T1
Muk lock hurts the most, either via Broken Time Space or
Ascension Grimer.
Goop Gas Attack can stop you too.
The problem with any of these broken Unlimited decks is yeah they win if they go first but they basically can't do anything if you take away their Trainers or Powers. More modern Unlimited decks seem to be better at coping with these locks because they have Abilities instead of Pokemon Powers/PokePowers/PokeBodies. For example neo BlastCune can use Blastoise BCR (before it had to use Emboar BLW) with
Suicune EX and it completely gets past the Power lock, unlike older BlastCune builds, and it can even employ its own Muk Lock to stop Vileplume or Porydonk or Crobat donk. Still, none of that matters if it goes second and it can't usually win T1 anyways.
Also I'd like to point out if you play Unlimited most people use
Sableye to go first instead of First Ticket because Overeager has priority over First Ticket's effect, meaning even if they play one Sableye makes you go first anyways. I guess you could play both, I mean I'm not really sure what's standard nowadays but I'm sure
Spiritomb still sees play and First Ticket would let you go first AND still use Spiritomb but that seems like a lot to play imo. But anyways just be aware if you play First Ticket you can't go first over Sableye.