As a reaction the user may replace one letter in a spell cast creating a spell name that could be valid.   


The ring has 26 charges (one for each letter)

Examples:
(E) Fire Ball - > Fire Bell   (Creates a ringing fire bell)
(R) Chill Touch - > Chill Torch (creates a chilly torch instead of chill touch)
(O)Power Word Pain -> Power Wood Pain (creates an Legendary Angry Tree Ent)
(F) Wish -> Fish
(D) Misty Step - > Missy Step

Notes: Debuff