I’m not going to do any spoilers, but reading some older Gloranthan publications I came upon a mention of a Rune Priest wanted by the cult (as in accused of a criminal act against the cult). The Rune Priest is listed as having Rune magic, so it seems the relation to the God is still intact.
Could a Rune Priest in trouble with the temple emigrate and continue as Rune Priest in another temple far away? Or at least participate in associated cult ceremonies? Or is there a relegation mechanism t