Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.
Hidden Strings says:
You may tap or untap target permanent, then you may tap or untap another target permanent.
Cypher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)
and Shock deals two damage to a target opponent.
Here's the process:
- Have Guttersnipe on the field.
- Play Hidden Strings; cipher it on to him.
- Play Shock instant.
Because shock causes guttersnipe to deal damage, this activates the cypher ability and you can now cast hidden strings, which will then cause him to deal two more damage, which allows you to cast hidden strings, which deals two damage, which allows you cast to hidden strings, which deals two damage.... and well you know where this is going.
Does this combo work?