Nissa, Empowered Animist

Credits to the artwork go to , originally a request done for me.

+1: Put a loyalty counter on Nissa, Empowered Animist for each Elemental on the battlefield.
0: Until your next turn, Nissa becomes a green Elf Wizard creature with power and toughness equal to the number of loyalty counters on her and gains indestructible, trample, hexproof, and overdrive. Any +1/+1 counters she has as a creature become loyalty counters when she becomes a planeswalker.
-10: All lands you control become 4/4 Elemental creatures with hexproof. They are still lands.

Overdrive is an original ability made by me. Its reminder text reads "If a spell or ability that targets this creature would give it +X/+X until end of turn, instead give it X +1/+1 counters."

To clarify on her second abiltity, she's treated as a creature and not a planeswalker while it's in effect. As soon as your turn rolls around, she stops being a creature and returns to being a planeswalker. Any +1/+1 counters she may have become loyalty counters.