For Wisdom of Sea, those cards were intended to feature legendary Pokmon Ho-oh and Lugia, the two mascot characters from 2000s Pokmon Gold and Silver
This means there are, supposedly, 15 total copies of these cards in circulation, or 5 each of the first, second, and third-place variants
Stories like the Brittons have been made possible due to the nostalgia for Pokmon from millennials who grew up with the Japanese trading cards
Aura-based removal is worse when creatures remain valuable, such as through cards like [casthaven]Wretched Gryff[/casthaven] and [casthaven]Aviary Mechanic[/casthaven] (but better alongside cards like [casthaven]Auramancer[/casthaven] and [casthaven]Thassa, God of the Sea[/casthaven])
This makes it an ideal build-around trainer card, as you can include a variety of Pokmon on the bench to give Mew-EX the ability to handle any situation