Complex sentence: Although Kinji learned about the special properties of the bullet and potential powers it gives from Holmes, Aria seems largely unaware of anything unusual about the bullet or herself, just that some stranger shot her for an unknown reason and the bullet can't be removed safely.
Split into simpler sentences: Although Kinji learned about the special properties of the bullet and potential powers it gives from Holmes, Aria seems largely unaware of anything unusual about the bullet or herself. Just that some stranger shot her for an unknown reason and the bullet can't be removed safely.