Neil

After collecting two notebooks in Neil Mode, Neil will spawn either at the long hallway or near Raldi's Bank and chase the player in a randomized but steady pace. Neil is much faster than Raldi and it's important that the player uses their gas canisters to their survival. It is also worth mentioning that he can also break windows as a shortcut towards the player. Collecting all 10 notebooks and reaching the fourth exit starts the 2-phase boss fight. This is from the wiki, thanks wiki! ^_^