As the last ability resolves, the enchanted creature is put into its owner's library. After it resolves, Shattered Ego is put into the graveyard from the battlefield.
2021-06-18
If the enchanted creature's owner has two or fewer cards in their library, the enchanted creature is put on the bottom of their library as the last ability resolves.
2021-06-18
The creature will be put into its owner's library even if Shattered Ego is no longer attached to it as the ability resolves.
Enchant creature
Enchanted creature gets -3/-0.
: Put enchanted creature into its owner's library third from the top.