The System is like a one of a kind parasite. Meaning that no one else would have a System. It chooses it's own Host, in other words, Justine to be its Host. However, unlike a parasite, it does not hurt the person that they attach to.
It carries unique items that cannot be bought with just money. The System has its own currency, namely Life Credits. Life Credits could be obtained by gaining achievements throughout your life.
For an example, saving someone from the hands of a kidnapper may give the Host roughly 10 Life Credits. However the amount of Life Credits may change proportionally to the person that was rescued. Compared to any random person on the street, rescuing a prince would give the Host around 100 Life Credits.
Another method was to rank up. There are 9 stages in the world of Astralin. All races undergo the same process, however some races naturally have higher talent than other races. If the Host ranks up, they would be given Life Credits for becoming stronger.
While it was explained how the System became flawed, for those who didn't read carefully this is for you. The System is managed by two people but in one body. One is mature than the other and the immature one picked Justine as the System's Host. However the mature one didn't like that idea so they had an internal conflict, which resulted them in breaking apart. This caused the System to become flawed, hence "The Flawed System."