This has the same effect as Brudiclad, Telchor Engineer
Its important to remember that this is a persistent effect without a specific owner, so it will continue for the remainder of the game, even if Vadriks owner leaves the game
Everything after that is just an extra card every time you cast a face-down creature
This creates a two-card combo where one Pokemon can generate the Energy while Dawn moves it to a Pokemon you want attacking
I'm not against using it to self mill to get a win with Jace, which sounds like it'd be a VERY good win con combined with Archmage Emeritus, Thousand-Year Storm and Veyran, Voice of Duality, or to fill the graveyard for me to cheat something out with Narset, but I wouldn't really consider that ideal in that circumstance because the ideal situation (in my mind, at least) is I'm using Narset to cast something twice