
I actually also don't get it..
They're maybe not best friend, but they close enough to meet up after long time not see, more close than just regular classmates in highschool at least...
And monkey clan have many people, since they was majority.. it not like other clan who only have a little members... So it's kinda weird to choose or believe in someone he just meet than his old friend...

that hyung was brainwashing him. So it is obvi that what he would say wouldnt make sense. And that friend isnt mad at MC. He was just brainwashed by that hyung to make MC as a sacrifice or rather a statement to ruin the carnivores' reputation. Also the aggression was already because of the drugs that hyung made him take.
I don't get it they were friends but the second he found out he's a hybrid suddenly it's all I'm gonna hunt you down and kill you like bruh