... no? Having physical matter =/= being bilogical beings (Hence you know... INORGANIC PHYSIOLOGY in the Monster Physiology page)
that's not how this works... specially when, in nature of being a literal skeleton, he literally physically lacks what is needed to even have a migraine to begin with
Yeah... which is why him being a skeleton is the bigger role here, he literally has no organs, skin, blood vessels, etc, whatsoever... he quite literally CAN'T have a migraine... due to him not HAVING what would make one possible
Which, again, makes him not have internal organs... or biological stuff
Physical Matter =/= Biological Matter... that literally means nothing
Plus... you assume Magic is incorporeal or something? Pretty sure we were never told in Undertale
The ability to be made of inorganic matter. Users of this ability are unaffected by many things which would be lethal to organic beings or even the undead.
- Resistance to Biological Manipulation: As users of this ability aren't organic beings, they lack all biological functions, and can therefore also not be manipulated in this manner.
Again... that is just common sense? It is covered by Inorganic Physiology already, he doesn't HAVE biological functions even remotely similar to a Human like Kris for you to even argue he can have a migraine
Also... he is a skeleton, we can quite literally see through him all the time and huh... no organs, like, at all
He wouldn't, Inorganic Physiology quite literally covers this, plus... he's a skeleton like being, WHERE would he even be affected to feel a migraine?