Handplates

Well since you brought it up

Gaster deactivated the lasers, stepping into the room. "You two-" he began before seeing S-1 holding his detached arm and waving it around in the air. "What?" asked S-1 smugly. "Somethin' wrong? 'Completely normal and entirely painless' you told him? Nothin' wrong with taking your arm off, right?" he continued, leaning back against the wall. Gaster just stood there, watching the smug little skeleton. "Unless there's somethin' about this arm, or maybe this hand, that you want us to keep on. Hey, how about I just leave it here today?" S-1 continued, placing his detatched arm on the bench. "After all, it's not like you'll lose it or anything..." S-1 continued again, even more smug this time. Gaster paused before letting out a sigh. "Alright. I don't have time to set up a proper lesson, so we're just going to do the short version. S-2 come here." he said, rubbing his forehead tiredly. "Give me your arm." He said, detaching S-2's arm and holding it in two hands. "Now, go stand over there." Gaster instructed, pointing to a far corner of the room. S-2 obeyed and stood in the corner, tilting their head questioningly, so innocent. So testable. With a pause Gaster applied pressure to the detached arm and... 'SNAP!!!' With a loud breaking sound the bone broke and the sound was quickly filled with S-2's screams. "The limb may be physically detatched and immobile, but it's still magically connected to the skeletons SOUL in question, with all that entails." Gaster said over the screams and S-1 ran to his S-2's side. "Oh my god are you ok!? oh god!" S-1 said, his eye beginning to glow a blue colour. "I'll be taking this so I can set the bone. You'll get it back later." Gaster said turning and exiting and locking the door. "You really are too clever for your own good at times." He called to S-1 over his shoulder as he left.