Asgore’s already seen Sans try to look out for Papyrus, but he wanted to give him this peptalk of sorts because he’s seen before how talking about his low health gets him down (which in itself is residual damage from before), and he wanted to re-emphasize that Sans’s strength or value isn’t determined by his health. Sans thinks about this responsibility a lot from this point on.
We saw a similar SOUL silhouette before with Sans, and now we can see both the brothers! Both their SOULs are unusual. Papyrus wanted to wear something grown-up and mature for heading out on their own, which is something he associates with dark sweaters, for some reason…
Asgore waited until they were both out of sight before going into his empty house to weep quietly, one assumes.
You take your eye off Sans for five minutes and he starts getting into all your traumas! He does love dropping bombshells. Also saying things that make you feel really terrible about what you’ve done.
Spends so much time in there you’d think he was taking notes or something…
And Sometimes a Potato 