Sorcerous Origin: Yuan-ti Ascended (5e)
Original Yuan-tis were created from human¸ yours doesn't have to be. This sorcerous origin will take you through the evolution and the perks of turning into a Yuan-ti. In my setting it was an botched ritual to awaken Merrshaulk that failed and turned the half-elf sacrifice into one of the most powerful servant of Merrshaulk and a vilain was born :) Available in French & English. Let me know what you think of it.