+Sans's character design is deceptively simple: a short, skeletal figure wearing a blue hoodie, black shorts, and pink slippers. Despite his often lazy appearance and love for naps and hot dogs, he possesses a sharp intellect and a deep understanding of the game's mechanics and player actions. He frequently uses [Puns](/wiki/Puns) as a coping mechanism and a way to lighten tense situations, though his humor can also mask a profound melancholic outlook on existence within the game's world. His catchphrase, "you're gonna have a bad time," has become iconic among players, foreshadowing the immense challenge he presents.
+In the "Genocide Route," Sans becomes the final and arguably most difficult boss, challenging the player's determination and showcasing his true power. His combat style is unique, focusing on dodging, exploiting invincibility frames, and using a variety of attacks, including bones, Gaster Blasters, and karmic retribution. Unlike other bosses, he is aware of the player's ability to [Reset](/wiki/Reset) and reload saves, often expressing his weariness with the cycle of violence and the player's persistence. His battle is a test of skill, memory, and endurance, designed to make the player deeply regret their choices.
+Beyond his role as a formidable opponent, Sans also plays a significant part in the game's overarching [Lore](/wiki/Lore). His connections to the mysterious scientist W.D. Gaster are heavily implied through various in-game elements, including the "Gaster Blasters" he uses in combat, his workshop behind his house, and the hidden dialogue that hints at a shared history. Fan theories often link him to past experiments, alternative timelines, and a deeper understanding of the game's universe, making him a central figure in deciphering Undertale's most enigmatic mysteries. His knowledge of the [Multiverse](/wiki/Multiverse) and his ability to seemingly transcend the game's rules further cement his status as a truly unique and compelling character in video game history.