Arcanine has always been a pseudo mascot for the earlier generations of the series, with prominent appearances in the anime and video games, and this card adds to that legacy for sure
Promo Card Legality can be found here: Promo Card Legality can be found here: Older cards that have virtually identical game text as currently legal reprinted versions may also be played, as noted in the list below
Anguished Unmaking Destroying a threat is good, but exiling a target is better: Those pesky death triggers won't trigger (because exiling ain't dying!), and most decks have no way to profit from exiled cards (unlike cards in the graveyard, which some decks are thrilled to have)
Jailbreak is pretty innocuous on first read, but when you consider that it can give an opponent a beater or other large dumb body and get you a combo piece out of the yard for just two mana
You have a token doubler in the command zone, and dont forget that you can activate that ability at instant speed both to pump up your own creatures and to kill your opponents
