I'm kind of surprised Corviknight is so popular. It seems a tad underwhelming to me every time I look into it.
Same tbh! With the leaks everybody was crying the new Flying/Steel type was much worse and unusable compared to Skarmory and those complaints didn’t age well. Nearly every team I face online has that, Rotom-W/H, and Grimmsnarl. It’s a good poke though and can run many sets: Bulk Up, Defog/Taunt, and gets Max Airstream with Steel type STAB if you choose to Dynamax it.
The only poke that has given me headaches with trying to build a balanced team with some checks/counters and some sweepers is
Galarian Darmanitan. If its banded, depending on what it gets in on it could bulldoze my team if I have nothing that can outspeed it. On the other hand, if its scarfed? It won’t hit as hard, but it’ll absolutely be able to get rid of
my offense if I have nothing scarfed myself(which Is what I ended up doing anyway.) Then it if needs to, it can dynamax to get around its own choice limitation for coverage >_<. I’ve tried using
Rotom-H on my team as the “go-to” check but people are prepared for that switch-in.
On the topic of Dynamax being broken, the most common all-around answer I’ve seen people use for it is
Mimikyu. I don’t use it myself so I can’t attest to how it feels, but obviously it works and is something to expect from opponents.