IzzRei

The One Ring doesn’t just protect from all colors, it protects from colorless things too. Color isn’t even a part of the card or its effects.

Still should be banned though because virtually every deck benifits from having it. When that level of ubiquity happens along with that price tag then it functions more like a gatekeeper in the format. Speaking of which, mana crypt being banning is very much a good thing based on the above point