Even if it is a possibility, your opponents will team up to remove Hellkite Tyrant, making it a waste of 6 mana
In TCG2, many such promos are readily available from booster packs and / or available through in-game trades, and coming back to the question of localisation, I can see how not putting Pokmon TCG2 to market in the 1999s West may have been about expectations management as much as the finicky affair of locking down 100+ new card translations for play
Couple that with the specter of another holiday season surprise re-release and even Japanese boxes around $300 look scary
2 Hail, Caesar Ave, True To Caesar Hail, Caesar is a precon that you could never update and it would still be great
Cryogen Relic A significant upgrade to Ichor Wellspring for blue decks, Cryogen Relic looks awesome
Vial Smasher has to be on the battlefield at the moment you cast your first spell