I dont think i have enough experience with the game to comment on power levels but what about this.
Display. While displayed bury to recharge a card from your hand.
During recovery succeed an intelligence or craft check to display instead.
So on your turn you could cycle your deck a little or mitigate some damage. Off turn use is limited unless you wanted to get a card out of your hand in case an effect is causing you to lose a random card.
I feel the recharge causing it to redisplay is thematically representative of an ioun stone.
