My first IoP. Made after reading the Bartimaeus prequel "The Ring of Solomon". It's inarguably overpowered, especially depending on which set of summoning rules you're using.
THE RING OF SOLOMON
Description: A simple ring of gold, inlaid with one band of obsidian.
Musts: A high concept related to the possession of the Seal. Some way of summoning and binding supernatural creatures, whether via full Thaumaturgy, Sponsored Magic, or Ritual:Summoning.
Skills Affected: Discipline, Conviction, Presence, Intimidation
INDESTRUCTIBLE: To the annoyance of many a demon.
THE SUMMONS OF SOLOMON: [-1] The ring's main power is to grant the ability to use diabolism at Evocation's speed and methods.
THE TERROR OF SOLOMON: [-1] Demons are mortally terrified of the Ring and it's wielder. Gain a +4 on Intimidation and Presence when using them on a demonic entity.
THE POWER OF SOLOMON [-5]: This is why the Ring is so coveted by every wizard and sorcerer in the world. Gain an automatic +10 to Control and Complexity when using the Ring to summon and bind demons. Also applies to the Evothaum, with Control and Complexity replaced with Control and Power.
THE CURSE OF SOLOMON [+2]: And this is why nobody is much willing to wear it. Actually using the Power of Solomon requires taking a mild consequence and 1 additional stress than would be normally gained from spellcasting. Even touching the ring is a Superb attack against Endurance-actually wearing the ring automatically applies the Extreme consequence of UNIMAGINABLE PAIN, which is only removed when the Ring is removed. The Ring also cancels out the Wizard's Constitution ability.