I don't even think the team should be changing cards after being released. I know it happened in the past (before I was here) but I am against it. It would be very unfair for anyone who paid a lot for a card and it turns out to be nerfed later and lose value because of that. Many of the affected players would never spend money on Splinterlands again.
We never nerfed Kitty, which is still the best card in the game. Tofu is legal in Modern while Kitty isn't but Kitty had a long time when there was no split and, after that, more than a year in Modern. To me, if Kitty was untouched, we should only nerf cards that are even stronger. There's even less reasons to nerf Nidhoggr. There are many weak cards in Splinterlands and all TCGs. It happens in high and low rarities. Nidhoggr isn't special.
What we certainly need is better testing before the cards come out and that applies to everything. Core sets, mini sets, reward cards and promo cards.
100% agree