Combined with low retreat cost and 120 HP, Greninja remains a staple in multiple archetypes
Obviously you want to complete a dungeon to effectively use this card, but it can be a decent way to start up the initiative cycle while staying in the mono-green game of ramping out
Unfortunately, we wont get another Lathiel trigger from this since well already be in our end step
Banning the best deck slap bang in the middle of qualifiers isn't great - the only thing worse would be not banning it at all
This card cannot declare an attack the turn it is Special Summoned." That would make it competitive, though not broken, and it would up the consistency and speed of the archetype as a whole
Still, White has lots of map and gnome tokens, so giving up something that doesn't matter seems doable enough for this to be pretty good