Lani, Gleaming Eidolon

Constellation - Whenever Lani, Gleaming Eidolon or another enchantment enters the battlefield under your control, target player puts the top 3 cards of their library into their graveyard.
When Lani, Gleaming Eidolon enters the battlefield, target player puts the top 7 cards of their library into their graveyard.
Legend has it her maddening magic can make whole armies of adept warriors lose their minds.