ʚ//𝐾𝑖𝑙𝑙𝑒𝑟//ɞ ²

The killer looks like the original, but his jacket is gray-blue with a fur-trimmed hood, his turtleneck is black, with his variable soul always visible in front (see below), and his shorts are white with black stripes. Instead of slippers, he wears gray-blue sneakers. His face changes depending on his state of mind.
Killer has a clouded mind, craving to kill or bring pain to others because it gives him pleasure. His soul is defective - it is something like a target on the side of the heart (if he even has one). This is the result of a perfect balance of the monster's soul and the human's soul (the inverted and normal hearts cancel each other out). He has four states: the first - the soul looks like the monster's soul, but is red and has a border; the second - the soul slowly rotates in the shape of a target; the third - the soul becomes a solid cloudy spot, rotating at an incredible speed (at this point it no longer pulsates, as if the heart has stopped); Nightmare is able to switch his soul into this mode. The fourth state is a kind of "berserker mode", in which Killer is completely uncontrollable, and the hatred from his eyes becomes almost solid.[20]

Killer!Sans spends most of his time in his "second" state. During this state, Killer is unpredictable, plays on his victims' emotions, and is also extremely cruel: he calmly kills others without feeling guilty. A black liquid begins to flow from his eyes, which is an immense amount of determination (or simply hatred).
Has all the abilities of the regular Sans, but they are more dangerous and painful - the bones and teeth of the Gaster Blasters are sharpened;
Instead of blood when wounded, he bleeds the same black substance (hatred), but does not notice it.
SOMETIMES HE LOVES THE TENDERNESS OF VULGARITY. HE HATES SEX. HIS EYES ARE NOT OBSTACLES, BUT ORDINARY BLACK SOCKETS.