apparently, lv was the first and only to split his soul into so many pieces. couldn't it be possible that doing so much damage to his soul would eventually backfire in some UNEXPECTED (note: i said UNEXPECTED) way? if you've actually read the books carefully, you'd know that magic is in no way a precise art. crap happens.
by the way, don't take this as me defending my theory. it was ONLY a THEORY!!! and, frankly, i really don't care that much. secondly, j.k. is the only one who knows exactly what happens (or happened), so just chill. i'm just as interested to know the truth (so to speak) as everyone else.
i love you all!!!!