"Does it look like I enjoy this?" -D
D was the best friend of M back in 2012-?. He was seen as a servant in M's eyes. D played a lesser role to M. D did minor things, in fact when M wasn't there, he tried to help Nicole. D was quiet and kept to himself more than anything.
D, when forced to do things M wanted, showed clear pain in his eyes. He eventually confessed he hated what he was doing and gained nothing from harming anyone, but he was too afraid of fighting with M.
After M moved away, D was finally free of needing to worry about it continuing any further. He went on to make better friends and still sees Nicole to this day, all things of the past aside.