A Heart So Cold and Wicked by Rebecca F. Kenney

He saved her from a murderer. But can he protect her from himself?

Kidnapped by a serial killer, Feather has lived in a remote cabin for years, surviving by cleverness and caution. One night, she unwittingly summons a Fae demon known as Krampus, who enacts vengeance on her kidnapper and leaves Feather free… but with nowhere to go and no memory of the family from which she was stolen.
Krampus, a vicious horned Fae with a wicked tongue, doesn’t want anything to do with a helpless human girl, though he eventually agrees to let her stay in his huge, decaying mansion as his maid. But Krampus isn’t the only monster in the house, which complicates Feather’s efforts to clean each room in the strangely sentient dwelling.
For his part, Krampus becomes increasingly obsessed with the brown-eyed girl he rescued, a fascination that makes him more vulnerable to the Fae-hunters who’ve been hired to kill him. When the danger becomes too great to ignore, Feather must decide what freedom truly means… and what she’s willing to sacrifice to gain it.

This standalone, spicy fantasy romance has wintry vibes but can be read at any time of the year. It features Germanic mythology and monsters, a medieval-fantasy version of a serial killer, and the Fae universe of the Wicked Darlings series.