Brann wasn't nerfed, he was removed.

I agree that Tank Brann was too strong. But the nerfs they made make it clear there was no internal testing before rolling them out.

As many smarter people before me have pointed out, Tank Brann has no actual tank mechanics. He stands in everything, he doesn't move enemies out of bad stuff, he doesn't gather enemies, he doesn't use defensives - he just has a lot of health and a hard taunt. His only role as tank was to be a bullet sponge with a lot of health.

With them removing his health, he no longer does anything. Tank Brann does not exist, now it's just a squishy NPC that will stand in everything that can kill him for 15 seconds before he dies. I have him in a 10-Delve right now and he can do absolutely nothing. He died just fighting a treasure wraith even with me dropping an LoH on him. Immediately walked back and swapped his role.

There is no longer a tank spec for Brann.