Ripper Sans

Seriousness and responsibility. Unlike classic Sans, who is known for his ease and love of puns, Reaper Sans is often portrayed as more stoic, thoughtful, and even melancholic. The weight of responsibility and the isolating effect of his power make him more serious.
Isolation. Reaper Sans' main weakness is the inability to touch others without causing death. This creates a barrier to building meaningful social connections.
Irony and sarcasm. Despite the dark role, he retains a sense of humor, although it is often darker and sarcastic.
Fear of loss. The work related to souls has taught him to appreciate what he has, but at the same time he is afraid to get attached, since loss is a part of his world.
Caring (in some interpretations). In some stories, Reaper Sanz takes care of her partner, protects him and can be reliable and attentive.
Wisdom. Working with souls has made him a wise listener — he does not condemn, but supports in difficult situations.

Reaper Sanz has a coffee addiction.
He likes puns.
He kills everything he touches. Because of this, he accidentally kills Chara, who (unintentionally) subsequently corrupts him.
Every time someone takes away a pure soul that has committed no sins, the Reaper becomes very weak and sick, and part of his soul decreases.
Reaper Sans can increase the time to 4 minutes.
Reaper Sans is powerful enough to destroy one timeline using all his might.

Practically omnipresent: exists as a conceptual embodiment of death itself, meaning he is present wherever death exists; Gaster also explicitly stated that he and Papyrus are omnipresent, although this could be more metaphorical than literal meaning.

Manipulation of Death: Being the embodiment of death itself, Reaper Sans is able to neutralize natural durability and instantly kill almost any creature with a soul. He can also kill most creatures with a single touch. His scythe, like his own attacks, can neutralize natural durability and instantly kill almost any creature with a soul.

Immortality: He does not age and can probably reincarnate or resurrect, even if he is killed.

Disembodied: this word means having no material body or form. Therefore, the Reaper's body is like a ghost; you cannot touch him, and it is impossible to physically harm him. Trying to do this will cause you to walk through it.

Dark Manipulation: He can create black holes or clones of darkness to aid him in battle, and can cover timelines with darkness.

Flight/Levitation: He has black wings that he uses to fly.

Teleportation

Weapon proficiency: Demonstrates impeccable control of his weapon, as well as the ability to summon it from nowhere. It can even extend it with an attached chain.

Gravity manipulation: one of his supposed abilities (it has been shown and claimed that his darkness attracts objects, whether it is his physical immersion in it, Undine's words that it attracts her, or the ability to create miniature black holes with her help).

Reaper Sans is a skeleton in a black hooded robe, similar to the one usually worn by Grim reapers. He has a rope tied to his robe around his waist and neck, hanging loosely from Gaster's small blaster. He also doesn't wear shoes. Black wings can appear and disappear for flight.

Sans was happy with what he had. Sacrificing the souls of sinners had been his business for centuries, and although he didn't enjoy it, he could handle it. Unfortunately, after he accidentally killed a loved one, he lost his mind and became suicidal, losing part of his soul. Toriel helped him by restoring his sanity.

However, his soul is still incomplete, and he is still partially insane. He's basically back to normal. Although sometimes he can still become uncontrollable and temporarily lose his mind.

Sans doesn't like his job, but he tries his best to hide it. In most cases, he is calm and hides his feelings. He can be cute and funny if you get to know him better. He's afraid of dolls and clowns. The Reaper is very afraid of Gaster.

additionally
Sanz from Reapertale is one of the main characters of Reapertale. He is the god of death, along with his brother, Papyrus of Reapertale. It was created by the god of magic, Gaster.