Not only does Spark Double circumvent the legend rule, but it can also copy a planeswalker
Its only really going to be played extensively in tokens or control decks, because losing your own creatures permanently sucks
This gave a strong starting core of Trickstar Candina , Trickstar Lycoris , Trickstar Lilybell , Trickstar Light Stage , Trickstar Reincarnation
Special Summon from your Extra Deck, 1 "Number C" or "CXyz" monster with the same Type as that monster you control but 1 Rank higher, by using it as material (this is treated as an Xyz Summon, transfer its materials to the Summoned monster), then, if possible, detach 1 Xyz Material from a monster your opponent controls and attach it to the Summoned monster
The strongest Magic-style names feel precise, flavorful, and mechanically imaginable