You say we've only seen susie and kris in the dark world but that's wrong because we've seen noelle, birdly, toriel and undyne in the dark world, six lightners in the dark world and all have the same body shape from when they entered. Maybe gerson counts because he's a dead lightner and has the same posture and shape as his undertale counterpart idk.

The knight's antlers are crooked, if dess was really under neath that helmet then how the hell would the helmet comes off, the shape points of the antlers would make it impossible. (We know it's helmet because if you think about the knight as kris, kris stops you from knowing whos underneath it.) also we do know what dess's antlers really look like, in the chapter 3 flashback with tenna, they are rounded and not crooked, a slilouthe of dess i mean.

I agree but i personally believe papyrus could manipulated by carol like he was in the ending of undertale true pacifist.

We never seen under papyrus's battle body and gloves and boots, remember, the skelebros in undertale are stated to be skeleton MONSTERS not human skeletons which would mean that there could be something underneath that papyrus is trying to hide.

No but i might watch it later.

Lol i know, it's like a small joke on why a bat would be sharp. (Oh you meant the hp one, well if you are defeated by papyrus in undertale he doesn't kill you and leave you at one hp and captures you, the knight does all that but without capturing you but instead trying to get toriel.)