It is the third Core Booster of Series 7
However, BlackGatomon's attack stats are pretty good, so consider using her for that, since there aren't that many great Rookies in Black
Still, her 0 and -2 is where shes going to do the most work, and its great you can choose to play her on either 5 or 6 This will have its moments, but this format also has a lot of tokens and creatures who give you value when they die, and when your opponent has those to sacrifice this wont feel worth a card at all, even with the poison counter on top If you can kill something with this, or have it help you win combat, it will feel pretty good since youre only spending a single mana
On the other hand with everything at your fingertips right from the get-go there's the option to hit the ground running and enjoy a customised experience
Amulet of Vigor is pretty good, too
This turns connive into pure card advantage rather than card filtering