With so little information and context its a guessing game :( do you know how many chapters or the names of the characters, anything?
https://www.mangago.me/read-manga/royal_servant/ maybe this is it theres no z tho
Yeah or this one:
https://www.mangago.me/read-manga/on_the_bit/
IT IS ROYAL SERVANT I LOVE U GUYS. THANK U SO MUCH. MAYBE I WAS THINKING OF THE ANIME VAMPIRE KNIGHT (THE WHITE HAIRED ML NAME IS ZERO) SKSKSKS
tHANK U SO MUCH U R THE BEST I LOVE U IVE BEEN LOOKING FOR IT FOR SO LONG SKWKSHAHHSAH(๑•ㅂ•)و✧
im looking for the title of this BL manhwa with a butler, white haired mc. i cant remember the plot cuz i only read chapter 1. i think it has the letter z on its title but im not rlly sure pls help