Death and Memories
As this is a world of MMORPG, death is not permanent for most, though the initial fallout of the Apocalypse would certainly prove that there are many nuances around this matter. When a character dies, they return to their associated respawn locations; Their allegiant Kingdom, or the Town of Beginnings which lies near Aincrad Tower. However, death is not without cost.
Items, People of the Land and Monsters all behave roughly in the same way when it comes to their ultimate destruction. Adventurers are generally considered special, due to their Auto-Resurrect ability - but the visual behavior is the same. When an entity's 'health' rating goes to zero, they generally shatter and then disappear - on rare occasions leaving items behind.
Certain special People of the Land, such as Heroes, may linger for a little longer - much like an Adventurer. This allows rare things, such as a Resurrection Item, to pull them back from the brink.
When an Adventurer expires, the spot they were in turns into a black holographic gravestone with a 24-hour countdown - and are unable to communicate or experience anything. To the Adventurer, it's a frustrating 24 hours of being unable to do anything (asleep), before they are auto-resurrected in their registered Kingdom. This used to be 10 minutes before the Apocalypse.
Each time a character dies in an emotionally charged moment, they lose a bit of their memory. Sometimes, these are important and defining moments in their past, like the marriage to a loved one. Other times, these are minor memories, like the name of their pet cat.
The importance of the memory lost tends to scale with the mental or emotional strain in a moment or state of a character upon loss.
As death usually only comes at the hand of Combat, we have added a feature to the Combat System that allows you to 'wager' your memories during such an event in order to have a longer staying power - or choose to retreat safely, placing this choice in the player's hands.
What happens when all memories are lost, or much of it, will be revealed before it should become relevant for most characters.
It must be noted that there are paths to 'true death' for a character. Suicide is one such path, though the results there-off are met with some measure of skepticism by those in the world due to various strange in-world artifacts that surround such a deed. The topic of some of these ways is dark, and generally something that consent-wise, is fully in the players' hands. However, further exploration of what these other paths are, and what this means, is left to be found out in-game.
As a character loses the memories that made them who they are, they become changed in many ways. Often, the basis of their personality isn't so quick to change; but to those who are haunted or urged on by a defining moment can change their entire outlook on life if they lost that memory. There are other important facts that will be revealed over time in regards to the effects of such losses.