Counter Spell sort of Dispel Magic Yes

If they try to Counter Spell your illusion as you are casting it I would consider that a waste so yes in that sense, but once the illusion is cast counter spell will have no effect on it. You would need Dispel Magic to get rid of the Illusion. Which depending on the illusion your enemy may want to cast dispel on it.

I think a better question may be "Could I use a deception check to imitate spell casting?"

Counter Spell? Sort of. Dispel Magic? Yes.

If they try to Counter Spell your illusion as you are casting it I would consider that a waste so yes in that sense, but once the illusion is cast counter spell will have no effect on it. You would need Dispel Magic to get rid of the Illusion. Which depending on the illusion your enemy may want to cast dispel on it.

I think a better question may be "Could I use a deception check to imitate spell casting?"

Counter Spell sort of Dispel Magic Yes

If they try to Counter Spell your illusion as you are casting it I would consider that a waste so yes in that sense, but once the illusion is cast counter spell will have no effect on it. You would need Dispel Magic to get rid of the Illusion, Which depending on the illusion could be possible.

I think a better question may be "Could I use a deception check to imitate spell casting?"

Counter Spell sort of Dispel Magic Yes

If they try to Counter Spell your illusion as you are casting it I would consider that a waste so yes in that sense, but once the illusion is cast counter spell will have no effect on it. You would need Dispel Magic to get rid of the Illusion. Which depending on the illusion your enemy may want to cast dispel on it.

I think a better question may be "Could I use a deception check to imitate spell casting?"