Scion/Eden/the local entity has been alerted of your presence and will view you as a threat equal to or higher than a full-grown entity. You have two and a half hours to prepare for their arrival as they prepare for combat.
If entities do not exist in the world you are in, the attack will happen within a month of your arrival instead.
(If you do not possess the power to stand up to an entity, pray to your god for mercy, for your opponent has none.)