I've forgotten the details of the demi-god rules Roderick alluded
to, and don't have a copy to hand. I'm not sure the following
thoughts really help Paul's particular requirements, nor how you'd
express it in 100 words, but here are a few thoughts...
- The "Extra Affinites" route. Take "n" affinities from
the "divine" parents to represent the "divine heritage". The
character gets these affinities regardless of what dieties they
subsequently initiate to (so if Paul took "Storm", "Balance"
and "Otherworld" and initiated to an Orlanth Thunderous cult he
would keep "Balance" and "Otherworld". If he subsequently changed
to a less stormy subcult (Books not to hand to check) he would
keep "Storm" where a "normal" character would swap it for the new
affinities. You'd need to keep an eye out for the dodgy
combinations of course (someone with a Combat affinity ought not be
able to join Chalana Arroy, of course but what about someone with
Storm joining Humakt?, Fire joining Yelmalio?)
- The "Active Feats" route. Take "n" "standalone" feats that could
be learned from the "divine" parents. These can be improved
normally, but do not form part of any affinities. You may allow the
character to take additional feats from the same affinities (but not
the affinites themselves unless they initiate to the parent) as play
progresses to represent the "divine" power growing, or manifesting
itself more clearly.
As far as becoming an initiate or devotee (or even disciple) I think
it depends on where you envisage ending up - Assuming that becoming
sort of god is the aim, a character like this who becomes a devotee
of one or other of his parents will likely end up as a Hero Cult of
that parent, possibly offering a feat or affinity from the other
parent. A disciple will most likely be remembered as a (new) aspect
of the parent god.
Of course one could look at Sartar or Pavis for examples...