I haven't had an issue with the card. I just checked my battle log for Diamond Modern. Out of the 20 battles listed, 6 of them used Nidhoggr.
Out of those 6 Nidhoggr battles, every single one of them was a Win.
Maybe I've just been lucky, but I can understand why @breakingbenjamin says the card is fine. I suppose I don't feel particularly strong either way. As a result, I will likely not vote for or against on this proposal.
Appreciate the thoughts here, Nate, and fair enough! Perhaps my opinion is a bit too anecdotal, but I really struggle to develop any sort of consistency with Nid - I know many other top-level players far better than I that report the same. At the end of the day, I made the offer to put the proposal out there on behalf of the YGG crew that purchased the rights to design the top summoner airdrop and were left feeling very slighted having received, objectively, the most poor-performing card of the bunch (according to all the data I've seen anyway). I see both sides of the tampering with cards post-distribution argument, but I feel the positive precedent here far outweighs any negative consequences. We'll see how this thing shakes out!