Nivmagus Elemental

• WWizards of the Coast2012-10-01
  Official Ruling
  You exile an instant or sorcery spell you control from the stack, not an instant or sorcery card in any other zone.
• WWizards of the Coast2012-10-01
  Official Ruling
  Exiling a spell is not the same as countering it, although the spell won’t resolve in both cases. You may exile a spell that can’t be countered.
• WWizards of the Coast2012-10-01
  Official Ruling
  You can exile a copy of an instant or sorcery spell to activate Nivmagus Elemental’s ability if you control the copy.

Rulings via Scryfall