Born as a bastard to Lurendail and Hagleith, who, as despicable as they were, didn't care about him enough to raise him, Apollyon grew up between homes in Haelun'Or, which was under the rule of Naelgauth Maehr'tehral .. being raised by a whole bunch of families, none of which clicked with him, took a toll.. but he managed to pull through until he was old enough to care for himself, he found himself suffering from getting attached to certain people and then having to leave them. But, he ended up making a few friends that stayed, which he was grateful for. They had strayed away from one another in their later years, but they were good friends for most of their youth.
Having been homeless for most of his life, he started to look for many types of faith. Trying to find a deity which he believed would benefit from worshipping, but he never worshipped. He made sure to keep an open mind though, but he preferred to make prayers to his ancestors, despite them being... well, ancestors of the people who just dropped him with a family. But, it gave him hope, and hope was all he felt he needed.
After he separated from the foster care, he made his way. Attempting to find an apprenticeship in a forge or some other work, so he could get out of the gutter he found himself in. He was used to being insulted, you don't see many High Elves near homeless and almost destitute. But, Apollo gets by, making sure to be an important part of the community, whilst keeping the feelings he feels towards others rather held inside.. not wanting to get into trouble for it.
