Also, I think the Honorblades are the Herald's uber-Shardblades. 9 of which are probably still stuck somewhere or other, and one of which was last seen lying next to it's unconscious owner. (he ain't dead, cause Brandon sez he gets an expanded role later and he can't if he's dead. )
(edited to fix highly-unfortunate typo)
He dies in the first chapter, is refered to as "having a tendency to choose seemingly hopeless fights and win them. He also had a tendency to
die in the process." and shows up in the last chapter, only to die (we know he dies because his blade drops to the ground). What gives you the idea that death does much more then slow the Heralds down?
More on-topic I think that there are two sources of blades.
1 - The Parshendi source (Odium) which is the source of Voidshards.
2 - The Knights Radiant source (Almighty) which is the source of Dawnshards.
From the second to last chapter we have the quotes:
(The Almighty speaking (Page 997 of the original hard back))
Life before death. Strength before weakness. Journey before destination. Speak again the ancient oaths and return to men the Shards they once bore.
(The Almighty speaking (Page 997 of the original hard back))You might be able to get him to choose a champion. He is bound by some rules. All of us are. A champion could work well for you, but it is not certain. And ... without the Dawnshards ... Well, I have done what I can. It is a terrible, terrible thing to leave you alone.
It is possible that the Swords of the Heralds are the Dawnshards, but I don't get that impression (though I checked and we don't get a name for the words of the Heralds, just a comment about them being "weapons of power beyond even Shardblades".
I think Syl would have no problem with a Dawnshard, it is only Voidshards that feel wrong to her.
I would also like to point out the existence of Shardbearers among the Parshendi, both Blade and Plate, and that when those Blades or Plate are captured that none of the Alethi can tell the difference between them and the Blades/Plate that they have.
We also know that during the previous Desolation there were thousands of Knights Radiant (10 orders of 200-300), each with a Blade and likely Plate, yet in modern times there are maybe 100 of each. I postulate that ALL the Dawnshards are missing, and the 100 or so Shardblades that are around 'today' are all Voidshards, captured from the Voidbringers during Desolations.