Syngenesophobia is a The Loud House fanfic by That-Engineer. It is available on Fan Fiction Dot Net here , and on DeviantArt here.

Written as a darker take on the episode "Brawl in the Family". Lincoln's actions result in the sisters (except Lily) collectively turning on him and giving him a No-Holds-Barred Beatdownthat results in him getting hospitalized and developing a crippling fear of his sisters.

The story is being translated into Spanish  by TheLouder1.