Outsiders

The rarest and officially non-existent category of beings inhabiting the multiverse. Outsiders are entities from outside of the 1000 Known Worlds, that have never been 'officially' invited to it. They have no relations to neither the System nor the Dark Lords (although the former does tend to incorporate them into itself whenever possible). Instead they tend to be alien in the most base sense of the word.   Their existence is something that isn't known to the Mankind as a whole. Even the Dominion's leadership is blissfully unaware of their presence. There are groups - typically the ones pertaining to Powers, like the Church of the Highmost or the Temple of the Seven) who know about them and considers them to be a part of their belief systems (for example the 'true' angels of the Church).   Even to them, it is still a matter of faith. Majority of the multiverse 'explains' the Outsiders as some particularly powerful and strange spirits, a 'level up' to the divine spirits, serving Powers instead of Gods.   They are greatly varied, but one thing remainds common - they are among the rarest and most dangerous (if not simply unbeatable) entities existing out there.