Wrenn and Six planeswalker from Modern Horizons was a huge success. Now we get Wrenn and Seven for standard, which looks not as good, but still pretty decent.
The first two abilities clearly synergize, but the third one is where you can really combo out with Esika's Chariot. You can use the vehicle to copy the Treefolk token again and again every time it attacks, creating more and more large tree tokens on board.
The ultimate ability is good, but hardly achievable.