There's some wiggle room, and while playing against decks that are all inside your bracket is ideal, you can usually wiggle within one bracket away from you safely
It can't be a natural part of the creature
Diregraf Rebirth is a five cost spell that recurs one dork from your graveyard to your battlefield and can be flashed back for another go around the bin
Sure, we could pay less to go get a Skyshroud ClaimSkyshroud Claim to do the same thing, but it wouldn't be an artifact creature that sacrificed itself, playing into all of the synergies that the deck is trying to do all at once
You ignore those targeting requirements if those spells aren't bargained, and you can't bargain those spells unless you can choose the appropriate targets
Suitable for trading, competitive battling, or as a valuable addition to any Pokemon TCG collection