If it changes zones, it will either cease to exist (if it's a token) or cease to be a copy (if it's a nontoken permanent), and so you won't be able to cast it as an Adventure
Shortly after this card was previewed, it dawned on most Modern players that this One Ring to Rule them All would become One Ring to Rule Modern for several reasons: 1) almost any deck can play it and/or wants to play it, 2) its ETB ability single-handedly shifts the state of the game, 3) it provides massive card advantage, 4) it's abusable
Notably, the card is still legal in Commander, which means if you can nab a copy of this massively rare card thats never been reprinted, you can employ some truly chaotic shenanigans with any number of commanders that care about graveyard stuff
Despite the presence of very similar options such as Soul-Guide Lantern in Standard already, there are still reasons for adding this classic version of the graveyard-exiler
Baylen climbs the ranks today thanks to three ways to safely tap your tokens and put them to use like a dice-worker board game