Ring of Sul Katesh

The arcane secrets of Sul Khatesh are whispered in your ear. Whenever a creature other than yourself casts a spell within 120 feet, you gain temporary hit points equal to the level of the spell. 

Additionally, you have ADVANTAGE on saving throws made to maintain concentration. Finally, after completing a long rest, the you can choose a signature spell of 5th level or lower. They can cast that spell three times per day without using a spell slot.

CURSE. If you wear the ring without attuning, you still hear whispers but they may not be trusted. Insight, Arcana, Nature, History, and Medicine rolls are made with DISADVANTAGE.