Level 6 Down (male child reader X sister Mugino Shizuri)

Born with immense power (y/n) was sent away to a facility to suppress his immense power. At the age of only a year old, his esper level was 6. This made him the world's deadliest toddler. The only person he would listen to was his big sister, Mugino. He loved his sister, even after she tricked him and had him sent away.
Now four years later, Mugino finally has the chance to redeem herself and be the sister her brother believes her to be.