Spark Double
Oracle Text
You may have Spark Double enter the battlefield as a copy of a creature or a planeswalker you control, except it enters with an additional +1/+1 counter if it's a creature, it enters with an additional loyalty counter if it's a planeswalker, and it isn't legendary if that permanent is legendary.
I reread this card after thinking it was going to be pretty OP... and realized it is not nearly as good as I thought it would be on my first glance.
The reason that clone was so good back in the day, and indeed Sakashima was in its day, was that you could copy your opponents guys. They had a carnage tyrant? Now you have a Carnage Tyrant. They had a Broodmate Dragon? Now you have some dragons too! (In each case for much less mana also...)
As it is, having and protecting one powerful planeswalker is already enough to close most games, do you really want to tap 4 mana to cast another one? Seems like the definition of "win more."
I definitely am not the best predictor of such things, but unless I am missing some tap-out "going spark-wide" strategy, I doubt this thing will see more than casual play.