I've tested out with the variant myself, and I am really concerned about your ratios
One such card is Skill Drain, an ever-present in the game for many years due to its paralysing effect on many strategies, which remains a trump card for any deck that wont also be impeded by its all-encompassing negation effect
They recently printed General Kreat, the Boltbringer which lets you stay on-theme, even if the damage output isn't as strong on Kreat
Your opponent can't really avoid playing Pokmon to the bench if they want to pursue their own gameplan, which powers up Suicune to deal at least 80-120 damage with every attack
So while this spell can cost as little as Red Red to cast, it is still a ten mana value spell
It seems that Koraidon is a bid worse than Miraidon because you will end your turn once you use its ability