Limadan would actually be very interested in Rhea, seeing her prowess with death magic. To him, it would be an enourmous advantage to his army. He will claim her power was given by none other than the lady of grey and ask her to pay tribute as such. Their powers are fairly similair, though, while Rhea's is fueled by actual magic, Limadan's arcane arts are fueled by his own corruption.
While he will not go in depth about his past, I'm fairly certain Rhea would understand why he's such a pious man to this bloodthirsty religion and why he is who he is now.