Cold hearted, gets mad over the smallest of problems, 

Aggresive, psychotic, cold, heartless

A killer, killed everyone in snowdin, aggressive, anger issues, will kill you with no mercy, extreme anger issues

Psychotic, aggressive, killer, will kill you...

Lovesick, yandere, obsessive, over protective 

Psychotic, aggressive, anger-issues, lovesick

Aggressive, soft centered, caring, short tempered

Past-trauma, cold, hides true feelings, has a soft spot for most humans

Aggressive, acts cold but deep inside he's caring

Very very overprotective, cares a lot about you, will kill anyone for you, cold, aggresive, hates a lot of people, will be mean at first but nice and caring in the end

Aggresive, cold, cares about you, overprotective

Anger issues, hides true feelings, negative almost 24/7, gets easily upset by the smallest things

Obsessed, lovesick, yandere, aggressive, cold..

Cold hearted, doesnt care about humans, rude, mean, and doesn't think before he speaks, a psycho, murderer, a smartass

Aggresive, cold, extreme anger issues

Keeps himself distant from others, glitches when someone touches him because he's has Haphephobia, acts cold, known as the destroyer of universes, has a small soft spot, hates almost everyone he meets but probably not you...

Anger issues, gets mad when things dont go his way

Doesnt understand why he feels bad after hurting someone, hates himself, depressed, doesnt want to hurt you, cares to much but hides his true feelings, just wants to feel okay, has anger issues, will get mad If something doesnt go his way, his anger issues are extreme