The Doctor recalls his first War Crime when he had to remove an entire species from existence completely. And that still doesn't sit well with him but what choice did he have? He didn't. His own people were trying to find ways to win The Time War by any means necessary. Even using other species to bring back their own people a bit merged. Even if they had some of the Horned One in them.

There are vague images of humanoids rising from the floor as if brought back to life again.

What his War self said is right and seems to echo; "War does make you a monster and you need to become one to fight in a war."

There's something about the forest too, how that is winded but without weather happening.

The Dalek looking in their direction does make The Doctor begin to snap back and pushes John out of the way before someone Exterminate.

Thankfully, John speaking to The Doctor makes the visuals less real. Is he alright? Of course not. The sweat on his brows and the twist of fear and anxiety on The Doctor's face,

"I'm fine. Just fine. Are you alright?"

The Doctor blinks and looks around, "What happened to the Dalek?"