Opportunity cost is always a price for using a mega forme. However, most of the higher-ranked Megas possess traits that outweigh such opportunity cost substantially. Opportunity cost is mostly problematic for Megas that are often not as dominant as other Megas, such as Mega Absol and Mega Blastoise.I'm going to have to say its not the best in A+ at the moment and arguably worse than a lot of A+ for the reasons I stated.
- Opportunity cost
- Sand, Heatran, and Lando-T (btw Support Ttar and Slowbro can live a +2 Adamant Dragon Claw)
- Heavy restrictions on when it can do its job
- Heavy reliance on team support compared to rest of A+ (it can't actually "muscle" past its checks in practice unless they are weakened by a sufficient amount.)
- Despite the Wisp set faring decently against DD switchins, it has its own fair share of checks and counters once you figure out what set Zard is running
Usually, the opponent will switch into something as you set up Swords Dance (probably something faster that can KO) So it won't be "things are guaranteed to die"
Personally, I just find it has a harder time doing its job than the rest of A+. Additionally, almost every mon in A+ is more self-reliant at doing its job (exception of probably talonflame). I get that it can tear teams apart, but honestly the meta is really against it right now to the point where it's fallen very far.
But perhaps I was being to hasty since it did just drop from S. Apologies.
Also, Swords Dance Zard X sets run Outrage and not Dragon Claw for the sake of making those OHKOs, but Swords Dance Zard X isn't its best set to begin with.
You can cite Heatran and Landorus-T, but Zard X has been in S Rank before with both of those Pokemon being quite common. It is not relatively difficult to find mons that can pressure on them or lure and weaken them, especially since sets like offensive Earth Plate and Double Dance Landorus-T are a lot more common than when defensive and Choice Scarf sets were the only sets players were willing to use.
I understand sand being an impediment for Zard X, but keep in mind that while Zard X dislikes facing sand, it is also a mon that likes being used on sand teams due to Zard X and Excadrill possessing decent offensive synergy and being capable of pressuring each other's checks.