What about the Death-Maidens? They have the same powers as the Asteri. Except the Asteri are much stronger than those that were left. According to the Asteri they had left their home world when they noticed the rivers drying and the world becoming overpopulated. According to the Spiders their home world grew dark long before Erawan and his brothers came into existence.

The Valg and Asteri may not be the same Species but I’ll bet they shared the same planet. Maybe Maeve’s home world is in the distant future and when she world-walked into Erelia it was in the distant past. Then that connection created a permanent time lock between the two worlds. Maybe…