Of course the pacing and scenery may be a bit different to what I described, but it's a basic storyline. It goes like "Go running really fast with other characters, get shot, wake up and see Aizawa tied getting tortured while I struggle to move (this is very common in dreams) then Ochako comes close but gets BTFO and Aizawa dies" .
I might be filling what words did Aizawa exactly say for example, I did imagine his face screaming. We do fill some spaces when waking up but I have no way of knowing that.
You never imagined for example you were playing a videogame that doesn't exist and it looked real? The brain can put together some advanced scenes sometimes.