This ability stops the opponent from evolving their active Pokemon, meaning all setup will need to be done from the bench
While it can take some ingenuity to meld these two archetypes together, it'll pay off massively
Planeswalkers with good board control options and high loyalty counts are hard to deal with, much more so than cards like Elesh Norn or Griselbrand
This serves as not only a disincentive to attack you, and hopefully to pass off some of the heat you might be gathering, but also makes your already beefy creatures simply massive
The math behind it hardly justifies giving it a place in your deck
What we mean by that is that though it can take up to a thousand cards, it definitely becomes pretty unwieldy to use, and youre probably asking for trouble in terms of the strain put on the binder itself