A small handful of ascended beings has departed from the philosophy of the Others, toeing a fine line when it comes to their rules against interfering with the affairs of lower beings. This includes Oma Desala, Orlin, Merlin, and (to a somewhat lesser extent) Morgan Le Fay.
See also: Ancients
Threads - Daniel encounters the Others in a realm between life and death, where they appear as diners in Oma Desala's diner ... who show no interest in him.
The Quest, Part 2 - Daniel explains his checkered past with the Others, who Merlin has also dealt with -- and who he fears the Ori will one day become powerful enough to wipe out.