Elesh Norn's second and third ability each affects a permanent's own enters-the-battlefield triggered abilities as well as other triggered abilities that trigger when that permanent enters the battlefield
The term "defending player" in the myriad rules (or any other ability of an attacking creature) refers to the player the creature with myriad was attacking, the controller of the planeswalker it was attacking, or the protector of the battle it was attacking at the time the ability resolves
I can definitely see this commander occupying a similar space as Nymris, Oonas Trickster , offering you a way to maintain a healthy amount of cards in hand in a Dimir control shell
Zidanes second ability isnt limited to triggering once each turn
This is still a great card
Of course it's such an amazing game that I've gone back to it many times over the years. Unlike Little, Bonomo did not hang on to his card collection, selling them all ($1,600 worth) once he decided to go all-in on his poker career