What trophy?
Believe it not, it was not the surpasses the master one. Which 'only' took me an hour or so. I didn't find that as tough as say, mile high club. It was not even the one where you have to finish the campaign on veteran. That has a glitch that lets you do it on easy.The Student Surpasses the Master?
The trophy that caused trouble was immortal. You have to finish the campaign without dying and reloading from checkpoint.
On paper it sounds easy! I put it on recruit thinking that it would be a cake walk. But I what I forgot about these games is bullshit can kill you even on recruit.
Grenades are one shot and melee is still just a two hit kill. Even on recruit. And friendly fire also voids the trophy and twice I killed my team mates because of no name tag.
Now, it's done and I never want to play that campaign again!