All the Legendary Pokmon are pretty powerful, but in terms of pure raw stats, Arceus is the strongest
Some builds are optimized for quick games, while others scale better in longer sessions, giving players flexibility depending on how competitively they want to play.
TAHK0 speculated on why the error may have happened, writing, Poke Balls went through a lot of early variations, with everything from the button placement changing, to how it opens differing, to even being depicted with the white on top. It could be that an early Pok Ball design actually did open like it does on the card back, but when the design was eventually changed to the opposite way, they forgot to update it on the card back before going to print, and it remains that way to this day
Apply Special Conditions : Some attacks cause effects like Paralysis, Burn, Poison, Confusion, or Sleep