When obtaining a Epic grade or higher Class/Groa/Mount/Weapon Illusion, 

it will enter a 7-day Pending Finalization state starting from the moment it is acquired. After the waiting period ends, the Class/Groa/Mount/Weapon Illusion will be automatically granted.

If you wish to receive it immediately, 

you must manually confirm it by clicking “Confirm” on the [Pending Finalization] tab within the respective menu.

While in the Pending Finalization state, you may also change the Class/Groa/Mount/Weapon Illusion to another of the same grade.