This set is going to be legal in Standard until 2029 at the very least, so it is absolutely worth getting familiar with these cards as quickly as possible
Prevents destruction by battle
However, given that even cards from just a few years ago are no longer tournament legal, of course the value of these cards is in their nostalgia and, especially with shadowless cards, their unique, rarer, visual style
Azula Always Lies Confront the Past Dai Li Indoctrination Decorum Dissertation Desperate Plea Inkling Summoning Necrotic Fumes Ozai's Cruelty Pest Summoning Ruinous Waterbending Scarring Memories
Once per turn: You can target 1 "Advanced Crystal Beast" card you control
For example, if an effect copies a card in exile and allows you to cast the copy, casting that copy will cause Ghost-Spider's triggered ability to trigger