What does essence scatter do?

The Essence Scatter resolves, countering Nessian Game Warden.

Can Target creature be itself?

Yes. Spikeshot Goblin is a creature, and unless it somehow gains protection from red, shroud, etc. it’s a valid target for its own ability.

Can you target a creature on the stack?

Yes, when targeting a permanent, creature, artifact, enchantment, planeswalker or land, it must be on the battlefield. When targeting specifies targeting a spell, it must be on the stack (like with counterspell).

Can you change the target of a creature spell?

The targets can’t be changed except by another spell or ability that explicitly says it can do so. 115.1a An instant or sorcery spell is targeted if its spell ability identifies something it will affect by using the phrase “target [something],” where the “something” is a phrase that describes an object and/or player.

Can Counter target spell counter creatures?

Generally yes, a counterspell can counter a creature. To clarify the terminology, any card that is on the stack (the zone where cards that have just been played are in as they wait to resolve) is a spell. If the card has the Creature card type, it is a creature spell.

Is enchanting a creature targeting it?

Yes. Guard Duty, like other auras, targets the creature it will enchant when it is a spell on the stack. Tarmogoyf is such a good blue card that you cannot pitch it to force of will.

Can you destroy a creature on the stack?

Costs don’t use the stack. If I cast Fling, you can’t destroy the creature I want to sacrifice before I sacrifice it—that just happens. “As” abilities generally do not use the stack. For example, with a Clone, once it resolves you can’t see what creature it is copying and then decide to kill the creature.

Can you deal damage to a creature on the stack?

Change: Under the old rules, creatures simply dealt damage to each other, and the only spells and abilities you could play at that point were damage prevention and regeneration. Under the new rules, damage goes on the stack, and then both players have the opportunity to play spells and abilities.

Is enchant creature a target spell?

Yes. Guard Duty, like other auras, targets the creature it will enchant when it is a spell on the stack.

What does it mean to counter a target creature spell?

Countering a spell means putting the spell card into its owner’s graveyard, unless an effect specifically puts it somewhere else (like Remand). The fact that a card specifies “target creature spell” just means you can’t use it on other kinds of spells that aren’t creatures.

Can you counter summoning a creature?

Almost everything you play is a “spell”. A counterspell lets you counter almost anything that you play (not necessarily everything that gets put into play). Creatures are spells that you play, so they can be countered. Once they’re in play, they’re permanents.