The Order of Ascension are a group of former Guthixians based in the Monastery of Ascension, found beneath the Feldip Hills. The order base its beliefs on Guthix's principles, founded and made to fight against the gods. But after the god's death, the order lost its path and have since begun experimenting on local villagers in order to create a new god to worship.
The Order of Ascension most commonly refer to the six legiones who lead the Order. These six legiones are powerful mages using magic learned from Guthix. They use this magic to experiment on villagers kidnapped from local villages in order to try to "recreate" Guthix despite his wishes and the wishes of the Guardians of Guthix, specifically Ocellus Virius, the Guardian outside of the monastery.
Slayer monsters that belong to the Order of Ascension are:
Any of these monsters can be killed when given an Ascension slayer task, along with the six legiones, though it is recommended to kill Gladii or Rorarii for their ease and good drops.
During Nomad's Elegy, it is revealed that some of the members, led by Legio Septimus, left because they felt their fellow Ascended did not do much apart from staying inside, feeding off the crystals. Sometime afterwards, they met Nomad and joined with him after he revealed to them that he had a project similar to what the original Order was doing. They assisted Nomad in defending the fortress and protecting his construct, but were unable to stop the adventurer and their allies.