Annul vs demons horn

[Shamrock]

Someone plays annul witch counters target artifact or enchantment spell demons horn did not do anything this turn and wasn't summoned this turn so does it send demons hit to grave yard pls answer fast in game now

[Moocow4u2]

You can only counter something being cast. Once it's out you can't counter the spell

[AkiraDeLaine]

To counter a spell it has to be on stack, right?

[Gorzo]

To counter a spell it has to be on stack, right?

Yessir