Angels, as you know, are not mentalities of their own, but are semi-independant aspects of the mind they serve. The longer they remain distinct from their parent mind, the more likely they are to become truly independant (like Michael and Gabriel of Adam, or Raphael of Patar-Ori), but they will always be reflections of their masters, and most often they will remain in their service (Lucifer of Patar-Ori is a clear counter-example, but he was stilled as Mercury in the first battle).
Guardian angels were at one time of the same ilk – very minor drops of Adam or Eva (or very early on, Lil)’s soul charged with guarding their person through the lifetime promised by the fates, and with guiding the person’s soul to the bosom of Patar-Ori between death and rebirth. In the latter turnings of Coera, however, when the numbers of man began to grow geometrically, and guardian spirits were in short supply, the guardians were designated for favorite souls, and the souls of Man left unprotected and unguided were tapped for their own guardians. So many modern souls seem poor and weak because the better part of them has been tapped to be their own genius.
Guardian angels, or “genii” (plural of genius), are the pilot fish of the souls. They are the Jiminy Cricket – the external conscience, that small voice that reminds you of things you’ve forgotten or what you should be doing. Sometimes, especially if the host soul is lucky, they are the source of creative innovation. Mostly, though, they are what their name implies – they are guardians of the life and the soul through the time allotted by the fates. The average time is 25 to 45 years, but some people have as little as a few days, and others are guaranteed well into their seniority. The average person is guaranteed as long as is necessary to raise their children. While the Fates can’t actually prevent someone from dying before their time, the guardian angels do their best to keep their charges alive and on-track.
In the past, people often died shortly after their alloted times, but modern medicine makes this less and less frequent. In the past, genii would linger to escort their charges back to Patar-Ori; now only the most dedicated will stay on; the rest will return to Patar-Ori on their own, or seek another soul to escort, or even set off to serve their own ends. Because not every soul is taken straight back to Patar-Ori, cremation is less of a safe bet and many religions have taken to burying their dead. Buried souls are often escorted in small groups to Patar-Ori, if they linger long enough around their grave, and are not first consumed or convinced to wander away.