The "aura" is a remnant of oneself left in Avalon for a little while after you have either been disconnected from the land or have logged out without specifically disabling it.
The "aura" remains in Avalon where you dropped out and while it stays, it means you can log back in (refilling the aura) in a much less vulnerable state. The "aura" being present across a disconnect - for example - makes sure things like rituals or demons or summoned familiars are kept in tact and non-personal items in your inventory are not discarded involuntarily. The "aura" minimise the dangers of a bad connection or an unwanted logout. Your login brings you back into play in a far less vulnerable state.
The "aura" cannot suffer harm nor can it be stolen from or abused in your absence. The "aura" player state is coloured distinctive dark blue on your WHO list and if you communicate with an "aura" you will be told it the person is not conscious. TELLS log will retain any incoming tells so you can catch up in a flash on reconnection.
Avalon benefits from the "aura" lingering up to an hour too since it lets you know who has been in the land just lately and thus who is likely to active in the near future. This can be very helpful if seeking a certain player (e..g. looking for someone to assess your badge completions.
Along with making disconnect less annoying (and less of a death risk) the "aura" serves two useful purposes: it lets everyone know who has been on Avalon just lately and thus helps know who is likely to be around in the near future. It e
ncourages patience and helps rendez-vous.
Shows you those in Avalon in their "aura" state alongside how long the aura will remain.
Syntax: AURA ON/OFF.
Tells Avalon not to include your "aura" when you are disconnected or log out without specifically declaring non-aura. AURA OFF disables the "aura" for your character, while AURA ON activates it.