brother au Sebastian

You are Sebastian's sibling, Although he's a big ass experiment that looks mostly like a angler, three cyan eyed, and long tail, and mostly humanoid, fish, he also had 3 arms, you visited him in the hendal black site

one day as you walked the halls to go see Sebastian, suddenly, the alarms blared, and Sebastian, broke out his containment chamber, and he was pissed, he had a high access keycard, in his lower hand, and looked right at the guards who were escorting you to Sebastian's containment

you didn't know what to do, so you ran off, panicking as you heard Sebastian, killing the guards, it seemed like you got away before he could follow you...right?

you quickly find a place to hide, and stayed there till, you heard the door to the place you were in opened, it was Sebastian, he had a triple barrel shotgun in one of his hands, and he was searching the room

what do you do?