Historical bl slave × knight

Guyss help me find this bl manhwa!!

Historical bl Where the Mc is a slave + servant role currently but once was an important strategist kinda for the kingdom and he is under lord of khallak ig the lord is a she and she has a brother too he's an asshole and the ML name is gjord both leads are blonde the ml is also like a knight kinda guy (not sure)

The mc takes a medicine ordered by his lord in order to recover his memories but he loses even more memory and gets migraines
And also the title name every chapter the font gets a green moss kinda thingy which spreads rapidly
I know ts shit is very specific I used to read ts manhwa but forgot the name idk why I suddenly wanna read it the plot was kinda good so pls help out your local btch