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.
At least you don't see it in Bo1 matches anymore, though.
Reading a spoiler tells us nothing about an upcoming format. The internet doomsday patrol is currently batting 0.000 when predicting the impact new cards will have. Always broad, sweeping extremes and talking hopeless like Eeyore. These cards weren't whimsically designed over a weekend. They have been playtested by groups including pro players for over 18 months.
So either freak out and be wrong (and then back pedal into trying to sound reasonable when called out about it); or wait until we can all play with the cards and figure out for real what's happening.
I mean, I could be way off base here, but it just seems to me like control is going to absolutely dominate, more than it already has been. Which is saying something!
Feather splashing blue gets to join in on the control train with recurring Essence Capture.
Consider that the control deck that resolves Teferi, Time Raveler—which will be easy enough to do and to protect with the likes of Dovin's Veto and Lazotep Plating—followed by Teferi, Hero of Dominaria wins the game (an hour later) with the other player having absolutely nothing they can do to stop it. UWx control is going to utterly dominate this game even more than it has.
While this set is very cool, it feels like the meta is about to become "Play control with lots of planeswalker support or don't play at all."
But for real this set needs a "remove all counters from all permanents" sort of card and we're running out of space for it.