mortal sorcerers who KNOW how limited they are and still want IN to the shadow hopping power plays of the Royal Family.
Further to this idea; but adding the thought that Sorcerers don't have the ability to travel through Shadow without other powers:EUGENIA
Ruled with an iron fist by the Secret Council, generations of selective breeding has made the population of Eugenia strong, healthy but lacking genetic diversity. Seeking a solution to this problem with divination spells, the Secret Council has learned that there are other universes, and powerful individuals who can travel between worlds. Possessing complete control of their Shadow, the Councillors have modified the Destiny of Eugenia so that males with the hereditary ability to 'walk between universes' seeking a warm bed will pass through Eugenia.
Eugenia is now a Construct with Named and Numbered Manifestations: the girls who will entertain the visiting Amberite. They have Flux-pin links that teleport each sperm cell individually to an assigned 'mother' - sorcery and technology combine to ensure that every conception will be successful.
The Secret Council hopes to breed an entire next generation (up to a billion) with the ability to travel to (and invade) other universes. Their plans will be slowed when they learn that inheriting the ability isn't sufficient to use it; however at that point they will change the Destiny of Eugenia to attract a Shadow walker who wishes to seize control of "the artifact that gives this bloodline the power to travel between universes" and offer him/her an army with which to do so. They will then establish that Amberite as a puppet ruler while they learn about the Pattern, and dispose of the puppet once it has outlived its' usefulness.