Ha'zas Syndrome, also known as "Illiadian End-Of-Life Wasting Disease", is a medical affliction that naturally occurs in Mikaru, Ree-Mai, Arrashes, Tirrdaka and Rakiakaru near the end of their natural life, though it can also afflict races like Dorro and Illiadian Humans if their natural aging is stopped through Ena-Based means. Since the bodies of these Illiadian races naturally don't physically age much after adulthood, they do not die of old age like other races. Instead, they die relatively suddenly, without showing any sign of weakness. This is very similar to Elves, but also different from them, since usually, one can not predict when exactly Ha'zas Syndrome might occur, unlike elves who can feel when their lifes approach their ends.
First symptoms of Ha'zas Syndrome seem much like the common Cold; sneezing, coughing, lightheadedness, fever, a lack of appetite... However, the condition of the afflicted will soon worsen, as they will lose their balance, start fainting, have their fever worsen, and eventually, the afflicted will go into a catatonic state. Bouts of consciousness will become less and less frequent over the coming days, and soon, the afflicted will most likely pass away from, what research has shown, their bodies not being able to contain their life energies anymore.
Ha'zas Syndrome has an extremely high mortality rate, since it is most likely the Illiadian's equivalent to old age. However, survivors do exist, and those survivors have shown that they have acquired a form of effective immortality; unless a survivor of Ha'zas Syndrome is killed by other means, like another disease or by force, they have the potential to live forever. There's apparently been reports of Ha'zas Syndrome survivors who would go on and live for dozens more millennia.
The Great Wasting is thought to have been a simultaneous, sudden occurrence of Ha'zas Syndrome that even afflicted people who normally do not catch it. The causes are still unknown to this day.