Having a card milled into your graveyard doesnt matter until its the last card in your library
This will be extra special should you have the chance to challenge twice in a turn through a reset, giving you a greater chance of taking out a big opposing character
If paired with green, black will sacrifice creatures primarily, but with red, artifacts can be melted down to deal damage or retrieve other artifacts from the graveyard
You can also make Jenova itself into a game-winning threat by equipping/buffing it, where it just does an Innkeeper's Talent impression rather than sac and draw sequences
Modern Horizons 3 The card quality is generally better in cards out of Modern Horizons 3 Play Boosters
Given that, I don't think we're really at a spot where energy is going to become a major player, though the fact that they utilized it here and in the Universes Beyond: Fallout Commander decks leads me to feel like we might see more eventually