They have no specific rules or mechanics affecting their usage, as theyre just slightly stronger versions of regular cards with close-up artwork and intricate holofoil details
It has a hollow body with a spectral ball of flame floating within
While triggering strange permanents is a nice bonusand if you are building around Naban, Dean of Iteration, it's certainly worth considering these cards (and cards like them) for utility slots in your deckif there's one thing we've learned from Panharmonicon, it's that most of the time, the right (and easiest) way to build around a card like Naban, Dean of Iteration is to play a ton of creatures with enters-the-battlefield triggers
Then you can print it out and use it as a guide when creating your magic proxies
For example, you can discard a level 7 or 8 Dragon to send an Arkbrave, or vice versa, which sets up an Arkbrave revival during the next turn
POKMON CARD GAME S9a 054/067 Double Rare card