Fun fact time! This is also lore. Spinel Seraphim (and this is cannon information), during the Genocide run against Frisk/Chara, she would’ve actually been walking across the Ruins, only to find Sans crying, holding Papyrus’ scarf, indicating that he has been killed by Chara. But Papyrus’ SOUL would’ve remained intact within the scarf because of his determination in his belief that ultimately got himself killed. Once Spinel Seraphim put on the scarf, it would then start one of many magical phenomena, such as Papyrus’ SOUL being able to speak from the scarf in Papyrus’ voice, along with the fusion of both his SOUL and Spinel’s, becoming a fusion of both Spinel and Papyrus’ SOULs. With renewed determination and with Sans’ disbelief of this situation-turned to pure ecstasy, Spinel Seraphim would then set out to stop the genocide, ultimately killing Frisk/Chara and to save the Underground.