Gaster hangs out with Arno alot and personally supervise him, Arno is very smart and reads book but he usally has Frisk's personality... he is picked on by Elys but not badly, like sibling fun he will fight back when he had enough. Sans left eye glows Red or Yellow when he is furious. Frisk is the monsters abasondor for relations and is extremely Sweet
Gasters wife Arial died by a human during the war and doesn't like to talk about it
Arno, Sans, Elys can use bones, gaster blasters, teleporting 