I'm skipping the sfx. You can guess it yourself.

Book: On Christmas night Santa comes carrying a large sack.
Alice: Santa huh...
Alice: There's no way he'd exist...
Alice: Sigh.. time to sleep...
Alice: Eh... Sa... Santa!?
Alice: Does Santa really...!!
Alice: Exist...
Alice: What's with this black Santa!?
Marisa: It's Christmas so I came for some presents~!!
Alice: Don't toy with my you stray Santa~!!

A black Santa comes to steal presents in Gensokyo's Christmas...

I turned your translation into notes. Because of the server load, they might take a few seconds to appear.

I love how you placed them so that the face is hidden.