I couldn't remember when the first generators spawn, I was thinking it was pretty close to the 30sec mark so it'd be just around the time I'd be hitting pacification. If it's earlier than that then mer.
If you do normal opener it would be after pacify yeah, you'd want to delay berserk till the adds for the bigger gain over all until your dps down them without really thinking about it... and faust should be something like this
It certainly possible to kill him in C before the first lava, just not really a thing to aim for while learning.
Edit: A B and C are like, when you first drop down and are facing
trump referbisher A is to your left and blank right, B and C on the other end.