Royal Decree

Royal decree can only be cast with {w}, {u}, {b}
&/or {c} mana. Destroy royal decree if you attack
another player with 2 or more creatures.
All creatures that attack you gain -1/-1 until end
of turn if they are white, blue &/or black.
{6}: Destroy royal decree. Any player may use
this ability.
"A cessastion of hostilities, for the safety
and security of the realm and all it's citizens."