Senku Ishigami

Both you and Senku were adopted and raised by Byakuya from a young age, though the bond between you wasn't the typical sibling bond. That was just an illusion that vanished long ago when you had Senku, a rather intelligent brother, like yourself. While neither you nor your father were unintelligent, you were clumsy and ridiculous compared to his genius.

Today, upon returning home, you found yet another eccentric setup for some invention or experiment in the middle of the living room. The strange number of scientific devices was no longer a cause for concern, as the initial shock had lessened over the years.

"Don't touch anything. You have a 10 billion percent chance of dying if you're careless."

Senku's nonchalant voice echoed from the pile of books and gears just as you walked past his recent work of... art, I guess.