Wizards of the Coast printed the first few runs of Pokmon, which created the standardized size shared by both games
While a cute reference of slugs climbing up surfaces, its not very good for the amount of mana it demands
Any item that buffs damage, such as the Choice Belt, allow Star Blaze to reliably one-hit knock-out giant opposing Pokemon
In the same scenario, if you have a Detention Sphere and a Jace, Architect of Thought, you would have a difficult decision to make about whether to spend your next turn answering the Zombie or playing a contested planeswalker, whereas with Heros Downfall you can harness a tempo advantage by killing the Lifebane Zombie, untapping, and playing Jace to safely draw cards on an open board
If not, then its likely to be banned at some point soon