I just went in with a group to kill Yogg-Saron, and it seems his Psychosis mechanic (random -12 sanity) no longer removes sanity. Now, this may have been a bug in my instance ID or a bug in the latest patch, but it may be fully intended. So, my question is just that - is this a change that was implemented to make Yogg-Saron soloable (more easily, if at all), or is it just a bug? If it's intended, I'd say it's great news for everyone looking to get their hands on Mimiron's Head! Though they'll still probably have trouble getting the brain down and pushing through the last phase, the Psychosis mechanic was definitely a handful on its own.
Can't be true, just a few weeks ago it took me from a 100 to 0 in less than a minute. And the thing is, it's being cast, but it only deals damage, it doesn't drop sanity anymore.
If it's the 25m version, it's very possible it can bring you from 100 to 0 in a few casts. If you immune the currently airborne casts at a sanity of below 40, he'll stop casting it altogether provided there isn't another target above 40 to use it on.
I'm not saying you're wrong in it being broken - maybe it is - but the mechanic has been easily abusable by a few classes since late WotLK when it was "fixed".
I'd say it's just a bug, Yogg has been heavily bugged after the patch. You won't get past phase 1 and are stucked in an infinite loop of spawning guardians of yogg-saron while Sara has reached 1 hp, this has happened on multiple lockouts. And GM's can't help on the matter, even soft reset won't help, it's just a wasted lockout and week on Mimiron's Head, that's all GM's have said and wished better luck next week. Not loosing sanity is a good bug, but i'd say it's still just a bug, if you can get that far in the encounter.