Specifically, the card allows the player to target one of their own in-play monsters, following which it cannot be destroyed by battle that turn though its ATK is halved until the End Phase
Recently I have preferred the Blaziken variant as it serves as good energy acceleration, but also serves as a tech against grass decks, which have been rising in popularity (more on that later)
Its effects will no longer be active
Stellar Sparks' Joltik is already a super powerful energy accelerator, and it'll pair gorgeously with the new Galvantula to load up masses of zap, ready to drop a nuke on your opponent's big nasty
If the spell or ability later returns the creature card to the battlefield (as Ephemerate might, for example), the creature card will return as a new object with no relation to its previous existence
Murderous Rider is one, a Throns of Eldraine rare zombie knight