What are you? Half-human, half... magic gem. The show hasn't gotten super specific about exactly is going on there, but Steven is definitely a little more than just human.
Do you exude some sort of supernatural energy or an aura? I'm fine with Kusu sensing he has powers, if you want! I don't know if they'd be anything really strong when he's not using them, but it's all still part of him.
Would you like to not be noticed? Nah, I'm cool with it.