Report a Bug
There is an issue with "It perpetually gains "This spell cost (2) more to cast"" not stacking on the same card. For example, If I use Nightclub Bouncer to send a card back multiple times to an opponent's hand, it doesn't stack when a enemy player cast that same spell. Here is a list of cards I've used with Nightclub Bouncer to exile it and return it to the battlefield to continuously send the same card back to an opponents hand. What ends up happening is the ability will show stacked, but the mana used to cast the spell doesn't change or the perpetual ability disappears.