If you use Shadow Movement to sneak into houses and a pegasus team to pull the flying sleigh... yes, in this world, it's possible to become Santa Claus! But... the Christmas tradition doesn't even exist in this world. When Rimuru tries to explain it in detail to the people of Tempest, they end up summarizing it as a "party." The Christmas cake and presents are ready, and most importantly, Kaijin and the other Dwarves create gorgeous decorations that bring the Christmas mood to Tempest. On top of that, Eren and the children treat everyone in town with their heavenly singing.
So... since you're a Demon Lord, 
I don't think he's gonna...
...لذا... بما أنّكِ سيّدة شيطان، فلا أظنّه سوف
Deshalb denke ich nicht, dass er
dich als Dämonenkönig besucht.
No sé si visitará a un Rey Demonio.
No sé si visitará a un Rey Demonio.
Du coup, je pense pas qu’il se déplace
pour un roi-démon…
Quindi non credo che verrà da un Re demone...
Então, se você é uma
Lorde Demônio, ele não vai...
Как понимаешь… вряд ли он решится
нагрянуть к тебе, Княжне Тьмы.