Essentially a form of attrition, you sacrifice your board or become harder to attack because your opponents lose their creatures as well
That said, you should definitely put them in a sleeve whenever you find one
This means that if they are too good, like Nexus of Fate, the promo nature of the card will limit its supply and make it more difficult to acquire and play with
How it works: A guide to MTG Cascade While the original Nissa Revane still sees some play thanks to its ability to draw elf cards straight from the deck, cards like Nissa, Sage Animist and Nissa, Worldwaker are more useful for drawing lands (and, often, turning them into creatures)
With Half-Shark, you can just keep returning action cards to your hand through challenging, opening yourself up to all sorts of combos and more importantly easy access to targeted removal when you need it
Detective's Phoenix Hailing from Modern Horizons 3, Detective's Phoenix combines a few interesting mechanics together, using bestow and collect evidence to put a unique spin on a Phoenix creature