Rulings
Mana produced by abilities of creature cards not on the battlefield, such as Chancellor of the Tangle or Elvish Spirit Guide, can’t be used to cast Myr Superion.
(wotc • 2011-06-01)
Myr Superion can be cast only with mana produced by the abilities of one or more creatures on the battlefield (such as Alloy Myr or Priest of Urabrask in this set).
(wotc • 2011-06-01)
Rulings
Mana produced by abilities of creature cards not on the battlefield, such as Chancellor of the Tangle or Elvish Spirit Guide, can’t be used to cast Myr Superion.
(wotc • 2011-06-01)
Myr Superion can be cast only with mana produced by the abilities of one or more creatures on the battlefield (such as Alloy Myr or Priest of Urabrask in this set).
(wotc • 2011-06-01)