Spare joker voucher:
A voucher that gives you a spare joker slot but the joker won't trigger if it's in the spare slot but you can switch out jokers based on your hand, this could be used for various purposes like keeping a certain joker safe from spectral cards that would destroy your joker. The voucher would have a second form(?) That would allow the player to store two jokers in the spare slot.
What do yall think?