This ability reminds me of a rare in Red (Raging River) that was printed way back in Alpha that divided grounded creatures into two sides of a River and then they could only block or be blocked by that side, so this is a clear call back to that, but color shifted to Azorius, which makes no flavor sense to me
Compared to last year which had that great video that felt like a love letter to the TCG and revealed multiple owner's pokemon, this year felt way more aimed at collectors with a generic trailer and more focus on the fancy art treatments
If youre fighting against Lightning Pokmon, you can pretty easily pivot away from Dondozo and use Stonjourner instead, powering it up with Tatsugiris Mise en Place, and then using Dondozo as a backup
It's a combo with Corpse Dance bringing it back for 5 mana, and then sacrificing for a key card over and over again
Its just a matter of whether you think Cosmium Kiln provides better upside than the early Wall token from the saga