Arena Rector

When Arena Rector dies, you may exile it. If you do, search your library for a planeswalker card, put it onto the battlefield, then shuffle.

The Wanderer

Prevent all noncombat damage that would be dealt to you and other permanents you control.
−2: Exile target creature with power 4 or greater.

Gold-Forged Thopteryx

Flying, lifelink
Each legendary permanent you control has ward {2}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Leori, Sparktouched Hunter

Flying, vigilance
Whenever Leori, Sparktouched Hunter deals combat damage to a player, choose a planeswalker type. Until end of turn, whenever you activate an ability of a planeswalker of that type, copy that ability. You may choose new targets for the copies.