Hero 5th: New Duplication Adders?

All,

I had an idea for the Duplication power, in terms of a hero built
around it. However, I want the total number of duplicates to not be
reduced when one of them is killed. I dont mind it taking a day or a
week or a month to come back, but I want duplicates that return. I was
wondering what would be fair for an adder cost or an advantage amount
that would let the duplicate numbers not be decreased with a death?

Also, duplicates cannot normally themselves duplicate unless they buy
duplication on their own. Still, they must pay (or soak) the cost of
the duplication of the original. Fair enough. What would be a fair
adder or advantage cost for letting them, instead of being to spawn
their own sub-chain of duplicates, merely act as a focal point for
collecting or distributing the duplicates of the original? Basically,
assuming I can make 8 duplicates, I want to make just 1, send it in,
and have it spit out 7 more. Or would that be unbalanced (esp with
regard to expendable/returning duplicates from my first adder)?

Finally, would there be a fair cost for an adder or advantage to have
no particular duplicate, or the original, really be the original? For
the concept I have, it is unimportant which ones are killed or which
one the original is. If the original is killed and the duplicates are
out and about then any one, all, or none of them could be considered
the original as far as I'm concerned (all will have exactly the same
point expenditure). However, the book (Hero 5th Revised) specifically
says that at that point the duplicates just hang around as individuals
from then on, unable to rejoin. I was wondering if it would be fair to
allow an adder or advantage which would permit that, and what the value
might be. It may not, esp in conjunction with the first one. The side
effect would be quasi-immortality, not counting age, but that isn't the
goal, just a side effect.

Of course, I'm the GM and this is an NPC so I could just ignore
everything, buy duplication straight out, and just make the powers work
like that. However, I just started wondering what values would be fair
for players (though none of my players now have duplication, or ever
will probably). I'm just wondering what others think of such adders.

Lewis