While a 5/5 indestructible beater sounds like a reasonable threat at first glance, considering that Historic will likely heavily feature Teferi, Hero of Dominaria, Teferi, Time Raveler, and Oko, Thief of Crownsall of which incidentally answer a 5/5 indestructible Darksteel ReactorI'm not sure the plan will actually be competitive
Its value is redeemed with four copies of 001-064-friends-on-the-other-side, which is an excellent song included in a lot of strong Amethyst archetypes
That's nothing compared to the duels, however
All Will Be One Hear only harmony
They even mirror each other, as one indiscriminately kills all of your foe's stuff but you lose 2 life for each dork that bites it, and the other just the tapped creatures but you gain 2 life
Winning: You win by taking all 6 of your Prize cards, or if your opponent runs out of Pokmon in play, or if your opponent must draw from an empty deck at the start of their turn.