mtg white card Top 100 Cards of All Time, Part 1 Top Ten White Card Flow

2019-06-14 Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to other creatures you control of the chosen type may become lethal if Morophon leaves the battlefield during that turn.

In case you didn't twig, the main spot for this card will be in dedicated land destruction decks which can get their own lands back swiftly using cards like Crucible of Worlds, or protect them with something like Heroic Intervention

And the graphic printed on the package

(2023-06-16) The last ability of Nazgl also lets you ignore the "singleton" rule in formats like Commander

Even if you dont have the three creatures you need, +2/+2 isnt a terrible backup plan