Out of all the cards currently available in MTG Arena's Standard format, there is one that is hated above all else - Nexus of Fate. On its own Nexus of Fate is not ridiculously overpowered, and in a best-of-three format it's entirely possible to deal with it in an efficient manner, but when it comes to MTG Arena's most popular best-of-one formats, things are not quite as simple.
First of all, due to the nature of best-of-one matchmaking, the vast majority of decks have very limited ways of interrupting Nexus of Fate decks. As you might imagine, this makes them particularly annoying to fight against since their entire game plan is to start chaining turns until you simply don't get to play the game anymore.
The second and equally major problem is MTG Arena's interface which constantly requires you to press buttons and confirm actions, all the while you're unable to actually do anything in-game. This alone would be bad enough, but if the Nexus of Fate player is feeling particularly evil, they can also keep you hostage in the match for as long as they're willing to loop their cards. It doesn't even matter if they can win the game from that point onward, because as long as they're looping they're completely safe. Not exactly an ideal situation, I'm sure you'll agree.
The demon itself
As such, I am very glad to say that the developers have now finally banned Nexus of Fate from MTG Arena's best-of-one Standard formats. It will still be available in Traditional or speciality formats, so if you're a fan of the card, worry not as you'll still be able to use it in the future. And if you currently own Nexus of Fate, worry not as you will not only get to keep your copies, but you will also be granted a Mythic Wildcard for each copy of Nexus of Fate in your collection!
If you're wondering why exactly the developers have banned Nexus of Fate, as well as why it took them this long to reach any sort of decision, you should check out the brief article over at the official website. It's pretty interesting stuff, even if you find yourself disagreeing with their decision.
And as a final note, it's also worth mentioning that the latest MTG Arena update has now fixed the recent Individual Card Reward (ICR) bug, added best-of-three Direct Challenge, made it possible to see which cards are revealed, as well as added a special Singleton event that offers alternate artwork for Duress and Ghalta. It's well worth checking out!