Illustrated by Daarken Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Legal Modern Not Legal Brawl Legal Legacy Legal Comp
Even with multiple reprints, with the most recent being the Enchanting Tales version from Wilds of Eldraine, this is because it's a powerhouse of a card
Flooding the standard carpool with cute fuzzy critters that will now stick around for another three years
Like most Pokmon cards, the value of Dialga G depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Platinum)
Stack a couple of activations on Yisan with the typical suite of Thousand-Year Elixir and Magewright's Stone and youre looking at three 5-mana creatures straight from your library to the field
As a bonus, this is also a pretty solid Naya commander