Can't Remember Title of Book?
I am having trouble remember the title of a fantasy book I read a couple of years ago. I remember that the title is the name of the main character and it starts with an M.
The plot involves a female assigned character who presents as a guy as part of their quest to get revenge on the person who took their best friend (because the friend was a bastard that they wanted to put in line of inheritance). The character is taken in and trained by this creepy old man and has a romance plot with the butler who initially thinks the character is a cis guy. The character has a faked execution because their old friend frames them for murder of the royal family's kids (because the friend wants to move up in the line of inheritance). The character ends up with the butler and they said across the sea together.
There's a subplot about the goddess of vengeance to whom the main character swears and oath and who destroyed part of the city before.
Also the character uses a poison to make their voice sound rougher so that people take them as a guy more easily, if that helps?