The Kenriths' Royal Funeral

When The Kenriths' Royal Funeral enters, exile up to two target legendary creature cards from your graveyard. You draw X cards and you lose X life, where X is the greatest mana value among cards exiled this way.
Legendary spells you cast cost {1} less to cast for each card exiled with The Kenriths' Royal Funeral.

March of the Machine: The Aftermath Promos

March of the Machine: The Aftermath

When The Kenriths' Royal Funeral enters the battlefield, exile up to two target legendary creature cards from your graveyard. You draw X cards and you lose X life, where X is the greatest mana value among cards exiled this way.
Legendary spells you cast cost {1} less to cast for each card exiled with The Kenriths' Royal Funeral.

Any of the exiled cards that somehow leave exile will no longer count toward the discount offered by the last ability.

The last ability doesn't change the mana cost or mana value of any legendary spell you cast, only the total cost you pay.