Funny, I also found Ishi and Chana in my recent WoK reread, but somewhere else:
They are the two ardents on the Reshi islands. He is experimenting with food, she is experimenting with sprens.
At one point he tells her: "You have to taste it first, you are the brave one!" - Brave being the first divine attribute of Chana.
I doubt that the beggar in Axis' interlude is a herald. He's missing some teeth which doesn't fit well with the herald's immortality and non-aging. Could it be that an Amian, e.g. Axis, is an herald?