That said, some items can break the rule
Regardless, this is a wildly powerful interaction in Standard, particularly if the Books static is able to be taken advantage of
If you sacrifice those heavy hitters, never fearAshling can copy them!Blight CurseAn infamous boggart spoken of only in whispers, Auntie Ool is the terror of Shadowmoor, known to dish out potent curses for the smallest of transgressions
She is always quick with a smile and a hug
While Mox Amber does require you to have a legendary creature or planeswalker in play to add mana, given the nature of Commander and the huge number of legendary creatures and planeswalkers Magic has been printing lately, it is very easy to activate
You can only use this effect of "Silent Magician Zero" once per turn