So I love a bit of exploring areas I'm not necessarily meant to be in, but broke the end of act 2 a little bit.

Went down the stairs in moonrise towers before fighting Ketheric on the roof and found myself in the mind flayers den with the blood lake where you can hear chop in the butchery, but can't reach him.

Turns out you can.

Either misty step or dimension door can be successfully cast to get you into the butchery, which if you proceed gives you no way back and lands you on a path to the final Ketheric fight without having faced him on the roof.

Not a great glitch or anything but thought it worth sharing none the less.