Cero Oscuras

You can't cast a legendary sorcery unless you control a legendary creature
or a legendary planeswalker
This spell can't be countered
Destroy Target permanent opponent control's
with converted Mana cost 3 or less
If you have at least 1 Crimson Cero in your
graveyard Change Flavor text
"Target" to "All" "Permanent" to "Permanents"