Why isn't Raboniel out there chasing Nightblood?

[Bloodless]

According to what we know of Nightblood, when it kills Fused, they are completely gone. No Returns. Nothing left over.

Nightblood killed the thunderclast Bob in the last book. People in Braize should be wondering "where the hell is our monster-mate Bob?". We can presume everybody, including Raboniel, should be hearing about this too. After all, a missing Fused is kind of a big deal for a bunch of immortals.

Shouldn't Raboniel be hunting down Nightblood to help free her daughter? And since it kills Fused, it is logical it will also kill Radiant spren. Another of Raboniel's end goals. Maybe she wanted to get into Urithiru not because of Sibling, but because of Nightblood?

Edited December 9, 2020 by Bloodless

[Karger he/him]

Certainly a possibility Raboneil would be interested in.  However NB is a kind of unreliable and dangerous weapon.  You can just see him starting a fused bloodbath.  Also Odium is probably being cadgey about NB's existence and capabilities.  Finally there is only one NB and if your war effort depends on holding and using him in battle it does not really change much.

[Aon Tia she/her]

We know from wobs that Rayse is scared of NB. He might not have wanted to draw too much of his fused’s attention to NB. 

Why arm the half crazy unstable fused that he has as his minions, with a weapon that can destroy Him as well. 
Raboniel may have been interested in finding it for sure but I don’t think that Rayse would have approved. No doubt she was all hush about her real intentions. 
These fused are so tired of the war, and Raboniel as much suggested that many of them would not mind killing their own god to finally end the war. Although it was clearly a lie but the thought has surely entered their minds! 

[ftl]

Raboniel might not have been awake yet at the time of the battle of Thaylen field, and so wouldn't know.

Or maybe she's had ages to plan this particular attack, and is just going through with the plan now that she's back alive.

[Aspiring Writer]

It could have been Nightblood that made her want to find a way to replicate it, as now they know it is possible to permanently kill a fused.

[IndigoAjah he/him]

What's she gonna do with NB? There's a very high chance she, and most of the people who could do it for her, can't be near NB without killing themselves on it. And it's in the hands of a very skilled warrior who, most importantly, has NB

[Raven Wilder]

There's only one Nightblood on Roshar, and no one knows how to make another (except for Zahel, who ain't talking). So you can only have one soldier at a time wielding a spren/Fused-killing weapon, and if it gets lost or stolen during battle, there's no way to replace it. Raboniel might not consider that enough to change the tide of the war; she wants to create an immortal-killer weapon that can be standard issue.