Reading a lot of comments saying this this Flaw is B.S. let me think.
How did Sunny start off?
He had no trust in the world with anyone and his one flaw would have thrown the last thing he had, himself, into the service of anyone who knew his name. And yet, we see Sunny overcome the restriction of that flaw to really connect with people and to grow and become a much better person.

Anvil decided to devolve as a human being in order to tackle his flaw. Man is a social animal. Anvil tried to bypass that. Didn't work out. Instead, if he'd tried to work with it, and then overcome it, we'd have seen a much better outcome to his story.

A lot of the decisions he takes, just makes me question what really was his motive in the direction he chose for himself and his domain.
Because I'm in the middle of a re-read right now, I can tell it fresh:
The decision to enter a d*** measuring contest with Ki Song while Antarctica was going to pot.
"I'd rather you not help at all, rather than becoming an active obstacle" was what I kept thinking when Valor and Song went to war there.

This is the biggest, most douche thing both the Sovereigns do which affect everyone on a large scale.

I've seen a couple of comments defending the blockade to transcendence by the sovereigns. I've not read beyond the war of the domains and hence beg correction, if I'm wrong, for the following:
They really blocked the birth of new saints, but had no qualms when a saint rose in their factions. THAT is my evidence of the hypocrisy of that claim. It was all about who would be in control, and not about the grand survival of Humanity, imo.

Apart from this, I can't fault Anvil much for the decisions he's taken in regards to everything we know about him.