Riddles in the Dark

The Deck asks you five riddles. Miss one & you die.
No resurrection possible! Win & get a magic ring!
The ring is indestructible & has an independent will.
It is a cursed item. It is evil. It can act once per MR.
It increases PPE & ISP +20% & Spell Strength +1
It can cast (or let the wearer cast) the following
spells 3x per day at Level 20: Charm, Oracle,
Invisibility Superior, Enemy Mind, Soul Twist
& Disharmonize. If the ring casts a spell on its
own, it has Spell Strength +6. It wants a mast