Lier, Disciple of the Drowned

Lier's last ability allows you to cast adventurer cards in your graveyard as Adventures and omen cards in your graveyard as Omens using the flashback it grants. This is because the alternative characteristics of those cards are considered when determining whether or not those spells can legally be cast. Note that only the Adventure or Omen can be cast this way. For example, if you control Lier and you have Bonecrusher Giant in your graveyard, you can cast Stomp with flashback, but not Bonecrusher Giant.

If a card with flashback is put into your graveyard during your turn, you can cast it if it's legal to do so before any other player can take any actions.

You must still follow any timing restrictions and permissions, including those based on the card's type. For instance, you can cast a sorcery using flashback only when you could normally cast a sorcery.