A UN empowered to do
what?
The UN isn't a war-fighting organization. It sometimes sends peacekeepers into tiny, local conflicts, but that won't work on superpowers.
Getting rid of the veto would do nothing in Ukraine. Even if the remaining powers decided to send forces, those leading the vote would be precisely the NATO powers.
The UN already serves as an important force in peace among superpowers -- not with weapons, but with words. It's a place where ambassadors talk to each other, daily, to smooth over conflicts and prevent them from turning into crises. It creates a world where cooperation and economic, rather than military, competition is the way to get wealthy.
It has worked well so far. This is the first time in decades that Russia and the NATO forces have come close to direct war. And it's bad, to be sure, but it won't be fixed by turning the UN into a warfighting organization to oppose them.
It has broken down because a superpower has decided to threaten its neighbor in a way that the rest of the world finally sees as a prelude to even more violence. That isn't fought by simplistic measures. It's being combated with economics, and via an incredibly uneasy reinforcement of that neighbor.
The key decision-makers are exactly those NATO countries who are most directly threatened. If Peru and Guyana and other countries would like a say, they're welcome to participate, but the countries at the forefront are exactly the NATO that you're so worried about.
The UN is not magic. It's not a world government, and nobody really expects it to be. It's a place for jaw-jaw to be better than war-war. When that breaks down, the best option is to use as little force as you can to drag it back to jaw-jaw.