- As yet Unknown.
It seems possible that the Arkenhammer is an artifact of changemancy fate magic, as the known powers are to alter walnuts and birds (nut->pigeon, orly->walnut), alter the holder's movement type(ground->air), alter the demeanor of dwagons(aggressive->subservient), as well as their side(Barbarian->GK) and fire lightning bolts(inert state->excessive electrical state). Further, the only known user attuned to it is a pure method of change(piker->warlord->Chief Warlord->Heir->Ruler), whose stated goal is to alter the face of the world(warring states->singular empire). On the other hand, any "effect" could be said to be a change from one state to another and could thus be included in the above list. Virtually the only power that would not fit "changeamancy" would be to do nothing, or to prevent change.
Changemancers may be able to affect the specials of units. Example, changing a certain unit so that it grows wings, giving it the flight special. Or possibly just the caster, like David Bowie shape-shifting in Labyrinth (the only known Changemancer being named after him).