Like most Pokmon cards, the value of Vaporeon 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 (Call of Legends)
Im definitely hoping for the former
I grew up with a giant cardboard box of old cards under my bed, but as an adult, I cant imagine putting in half the time or money I did into it as a kid
Initially, it acts like any other planeswalker, sitting out on the battlefield and is able to be attacked like usual
However, all of the duel opponents as reapers have been changed to protagonists, and the 2:1 tag match with Lawton is also played with the protagonist
But when you can be casting creature after creature that draw you cards, ramp you lands, and remove problems from the board, the fact that this relies on combat damage just gets to be kind of a nuisance