It's a key piece for certain hatebear strategies on the Reserved List
With multiple potential effects to choose from, with enough black mana Doomsday Confluence can build up your board, destroy your opponents board presence, and send their hands right to the grave, effectively locking them out of the game in one fell swoop
And because the skeleton cant block, this isnt like an installment plan against aggro
Legendary Commanders When green and white mana come together, they can build a powerful midrange deck that can do a bit of everything, and there was a Zendikar Rising archetype like this too
And if you can get extra lands off subsequent hits, all the better
Additionally, Disney Lorcana s quick start rules note, Disney Lorcana is a strategy card game where each player makes their own deck before the game starts, and the decks arent mixed together