So the cd task is similar to that competition where people made new slits. Like orb slot or there was a helm slot.
Of course it doesn't have to be a slot.
In that case change the title because a new mechanic is not what you meant to say.
Naesala and Chapuz: Please correct me if I am wrong.
An orb or helm slot would still be a permanent. We need to create a new type of card (Creature, Permanent, Spell, ...) not a new subtype of card (Shield, Weapon, Orb, Mark, Helm, Wand, ...)
How this new type of card would work is the mechanics we are describing.