Once in play the persist ability lets the Shepherd sit as insurance against wrath effects for all the non-persist creatures you might have, or any that already used their persist ability once
There are plenty of ways to combo with Sidisi, giving you near infinite Zombies, mill effects, you name it
The Blue/White deck in the format likes tapping things too, so getting some additional value here isnt impossible
This bit is important because Helga is designed to power out creatures with mana value four or greater
Instead of evolving Dunsparce into Dudunsparce (PRE 80) , you can go into Dudunsparce ex (JTG 121) , slap on an Enriching Energy, and not only draw four but also power Tenacious Tail- an attack that can easily push 180+ damage in the mid-to-late game
However, I'm a little disappointed that it's another Charizard chase and another Charizard-focused set