When the chunin exams erupted into chaos, he finally let go.
Not in words, but in feelings. A spike of rage when Naruto laughed too loud. A cold satisfaction when Sakura flinched from his silence. The seal fed on every grievance, every memory of Itachi standing over their parents’ bodies, and turned that grief into a blade aimed inward. Sleep became a battleground. Sasuke would wake with his fist through the wall, the black markings crawling up his jaw like living vines, his chakra tasting of iron and snake venom.
In the days that followed, the seal whispered.
He would open the door himself.