Shadowed Succession is a Harry Potter fanfiction series by AetherNarrated.
Book 1: Harry Potter and the Serpent’s Shadow
Elder twin Harry (the neglected shadow twin) is sorted into Slytherin and begins his long game. Inspired by Prince of Slytherin and Sarcasm and Slytherin.
New chapters released weekly.
Text available on AO3 and video version on YouTube.