I actually don't think Zygarde is broken. It has a lot of natural defensive counterplay—unaware Quagsire or Clefable on stall, Buzzwole, Slowbro, grass Knot Tangrowth, etc. There is also a lot of offensive counterplay: teleport/u-turn into infiltrator Dragapult, anything with a strong ice move can force it out, etc. Kyurem-B existing also gives the snake a lot of trouble because it gets fried by icicle spear. It's certainly very good, and has the ability to pick its checks to an extent (Toxic vs Glare, Rest vs Sub) but I don't think it's broken.
In terms of Zygarde + tspike, one of the best Zygarde answers is Heavy Duty boots Buzzwole. Kyurem-B often runs boots. In a pinch, most defoggers can take a hit from Zygarde to get TSpike off, and Pex can take an unboosted Thousand Arrows when it pivots in. if Zygarde is banworthy, it will be banworthy on its own merit, rather than because it's broken with tspike support. Tspike is usually very good in the early meta because people spam mediocre hyperoffense teams, and Zygarde + tspike being good probably reflects more on that than on whether Zygarde is broken or not.
This Pokemon is definitely one of the best checks to Spectrier and Spectrier has a high Usage being placed in the Top 10 on Rank 8, so it isn't surprising seeing Mandibuzz climbing all the way up to check this and also Dragapult in the current metagame. Mandibuzz serves as the ebst check to them as it has the longevity to serves as such. Blissey and Chansey might be immune to their Ghost-STABs but Dragapult can still get past them with Dragon Darts, especially when these 2 Pokemon are on low HP, or they got Knocked off in the earlier part of the game.
shot up too, with being Rank 1 here in the Crown Tundra Cup Round 2, and 
being up there as well on Rank 4 means these 2 Pokemon define which are the top-grounds currently, with checking Pokemon such as Regieleki and Tapu Koko. Zygardes versatility speaks for itself, with Dual-Dance (DD and Coil) and also Tarrows, Glare, Coil, and Substitute, which is its best Set currently.
and 
s Usage decreased as Players figured out how mandatory ground-types are in the metagame now, with Zygarde and Lando-T being placed in the Top 5, and also Swampert, which can be used on Rain-teams to get the slow momentum via Flip Turn and helping against opposing electric-types and giving Rain-teams the necessary true electric-immune slot, which is shown in a solid Usage-Winrate-Stat: 25 | Swampert | 25 | 6.76% | 64.00% |
pretty much stagnates from Round 1 to Round 2, same goes to the combination of 
and 
but I think Sand-teams are still the best archetype, when it comes to weather-reliant teams.
is a top pick in the metagame, as it can check many Pokemon with its Specially defensive-set, but its usage doesn't end there as to why it is a top threat, being used on Trick Room and occosionally on Sun-teams spamming Eruption clearly helps Heatrans Usage in 2 Rounds, as it was Rank 5 last Round and Rank 3 this very Round. I predict that it'll end up in the Top 5 next Round again, as this Pokemon is just an amazing pick overall and can fullfill many important roles in the current metagame.
Shot up in Usage as well, as I think that many people figured out that Veil-offense might be the way and acts as an Anti-Pick to Pokemon such as Swampert, which actually checks Regieleki very well, so people use the threatening Veil-Setter A-Tales instead to put pressure on especially Rain-teams with their leads being Pelipper or Swampert.
