What are Shardblades?

[Vortaan he/him]

I also like the idea that the Shardblades and the Thrill are of Odium. It seems to be reinforced by the line by the female Shardbearer in Dalinar's vision.

Sounds like the Thrill is something that happens to Rosharians when when they fight, and the Knights Radiant seem to think that it needs to be controlled and contained.

Random Theory Time: Odium made a deal with the Heralds: they stay with him between Desolations to be tortured while Odium provides weapons that can slice through anything. Odium takes the deal because he gets people to torture and a bunch of people going around with crazy powerful weapons. The Heralds/Radiants take it because they need the edge in the Desolations. But the Radiants think that they can control Odium's influence by relying on Honor - they use bonds and oaths to keep themselves from being corrupted. But normal people, without the oaths are completely susceptable to the influence.

I actually like this theory. I've always kind of figured the Oathpact was with Odium, not Honor. It also kind of leads into the Recurrence, where perhaps Odium's influence grew too great and the Knights Radiant walked away rather than turn against the world. This especially makes sense if Odium is as smart as Ruin and can play the long game.

If your goal is to conquer/destroy Roshar, and you are a god with no particular need to rush, set up the Oathpact so that Honor and Cultivation think they are safe. Make the lynch pin men, who after centuries of being sent to a torture filled after life are almost guaranteed to break their oath. The breaking of the pact gives you the power to shatter Honor, perhaps around the time of the Recurrence. The shattering removes the restraints on the weapons you created (Blades), so that men start fighting among themselves... and a couple thousand years later when you are ready to take Roshar, there is no Shard to fight against you, no Knights Radiant to lead the people, and the greatest warriors in the world are fighting against each other for weapons that could be their salvation if they were pooled. Sounds almost like Ruin's long range planning to get Vin to the Well.

[b4dave he/him]

I have a theory that the Shardblades are Splinters, ones that Honor conciously made before he died to give humanity a fighting chance against Odium after he died.

[Wisdom he/him]

I think BS has stated that Honor is still alive when the Oathpact is shattered, and Knights Radiant are already around before then. In the epilogue when we see this happening Kalak specifically mentions shardblades when he compares Honorblades to them. If BS has stated Honor is still alive then I don't think this can be true.

[Odium's_Shard]

Then the Oathpact consists of:

Give humanity badass weapons (Honorblades) and slightly less badass (Shardblades) swords to stand a fighting chance against your desolation.

Penalty: Those Herald people can be tortured whenever you like as long as they are home in time for dinner every Desolation.

[CrazyRioter she/her]

@Wisdom it's not always necessary for a Shard to die to create Splinters, as far as we know Endowment is still alive and can create Splinters (the Divine Breaths) at will.