Enchant creature Enchanted creature gets +2/+2 as long as it's an enchantment. Otherwise, it gets -2/-2.
A balm or a poison depending on how it is administered, and to whom.
Official Rulings for Nyx Infusion
4/26/2014 : Nyx Infusion continuously checks to see whether the creature it’s enchanting is an enchantment or not. If the creature isn’t an enchantment and becomes one, or it is an enchantment and stops being one, the effect will change.
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