so i got 15 loot boxes and opened them because i got a nice bonus and wanted to treat myself.

i'm terrible at deciding what to buy so i use loot boxes.

3 alistar skins, 2 rammus skins, a nasus skin, and 2 zilean skins.

so i reroll the rammus, alistar and zilean skins.

what do i get? another zilean skin( i dont even own him) a malzahard skin(who i also don't own) and ravenborn lb.

my question is

why the fuck does re-rolling for a random permanent NOT give you a skin for a champion you already own