Idk , Cruz isn ' t that great of a speller <| sep |> Well insanity requires that someone is unaware of reality in some way . There are pretty strict diagnostic criteria for mental illnesses . Brevik , for example , knew exactly what he was doing and was investigated several times in that capacity . He actually proudly declared that he was completely sane and that what he did was based on his careful interpretation of reality , not a distortion of perception . You can be sane and just be a complete fuck . <| sep |> Too late . it was a bit premature . <| sep |> Let me change your mind . <| sep |> Actually someone asked this to Araki before , and he said that he choosed time related abilites because he believes that controling time is the ultimate power anyone could have , so he gave that to DIO and Kira .