It creates an adventurer with no abilities and one hitpoint. This adventurer is not a thief, wizard, warrior, priest, or paladin. It goes first, even if there is a paladin, and behaves as a regular adventurer. This means a standard attack has to target it. “Attack Anyone” attacks can choose it as a target. “Attack Everyone” attacks affect all adventurers, including the illusion. Ghosts can’t attack it, but its presence allows them to attack the first real adventurer (even the paladin). If the party conquers, the illusion is the first to be assigned fatigue.

If the illusion survives the round, it does not disappear. It will lead the party in the next round. It can be affected by traps and spells.

Once the illusion is eliminated, however, it disappears. You cannot keep it in your prison, so you will score no points for it.