Even though you cant have two planeswalkers with the same name in play, you can have more than one of the same type of planeswalker in play as long as they have different names
To help address that, Banishing Light and Nylea, God of the Hunt have been added as cards that can beat an Elspeth (the most common answer is still just activating Polukranos, World Eater to kill the tokens and then attacking, or just overwhelming it)
skip your next Battle Phase, also Special Summon this card from your hand, then end the Battle Phase
Broodmate Dragon is very good at these tasks, because you get not one but two independent good creatures capable of dominating many boards on their own
Dual Nature Market Price: $2.13, Foil: $26.40 Kicking off the list is a watered down version of cards such as Doubling Season, Primal Vigor, and Parallel Lives
I also like this in shells like Discard-Matters combining this with Megrim effects, Reanimation, Midrange that wants card advantage ETB triggers, Blink that wants to have ETB stuff to blink over and over again and +1/+1 Counters-Matter where this is a nice way to add counters onto an ETB body