Kithercy Gellantara is a paladin of Amaunator and ally to the Dragon Friends. In The Less Theatrical Hobgoblin she is a guest in the Temple of Mystra, coincidentally where the Dragon Friends hiding out after being framed for the Duke of Daggerford's murder. The leader of the temple, Mistress Lorna, suggests a solution: the Dragon Friends should pose as her squires and servants on the way to Waterdeep.
Kithercy agrees to this plan only because she believes The Dragon Friends were innocent. (Technically true, but only in regards to this particular murder.)
Kithercy has a barded steed named Arthur.
She is Kithercy Gellantara, Paladin Of Wrath's Eternal Righteousness, Beholder Unto The Truth (KGPOWERBUTT)
She returns in I Step Into The Moonlight (1.12) as Davin Tyrril's captive and key component in his evil plan. Davin wants to sacrifice her and use her Lawful Good blood to awaken an army of Glittermen. In order to prevent this plan from coming to pass, Kithercy decides to change her alignment. She unceremoniously takes a dump on Davin's corpse, turning her Chaotic Good and preventing the ritual from taking hold.