The purebreds see themselves on a par (if not better) than the original demonic Angels.
They believe this as they have never been touched by “good” (as the Angels were – being products of God’s hand) but were creations made by Lucifer after the fall by his ability to introduce “pure” evil into human vessels. This pure evil twists and transforms their souls to be useless to Heaven – effectively eradicating the soul’s ability to achieve redemption or forgiveness. These vessels committed atrocities on Earth which there was literally no way back from and then went to their deaths in Hell happy to be there. Pure demons never felt remorse or regret regarding any of their actions on Earth.
Once dead and in Hell, the human vessels were reborn and reintroduced as members of several breeds of pure demon created by Lucifer (in much the same way as God created the animals on Earth). These demons then bred to create further sub-species (but always deemed pure).
Some have remained to have purely evil motivations (and allegiance to Lucifer), others have mellowed somewhat during their time on earth and have established alternative allegiances and motivations – but they all have evil at their core.
There are 4 forms of purebreds – all appear in human form: leeches, shifters, tricksters and soldiers.
From Fighting Spirit:
He was probably a pure-breed. No respect for differences, they lorded it over everyone. Pure-breeds were the assholes of the demon world.