Harmony's rhythm

[Dawe]

we saw in rhythm of war that it requires two people to combine even a small amount of two different types of investiture, as well as that the two people can't be trying to overpower each other, so how did sazed combine two shards by himself

Edited March 29, 2023 by Dawe

[Quantus he/him]

In the case of Lights, they needed two separate people to provide different Intents to push each pre-existing, mostly external Light toward a common average/center.  

Taking up a shard is a whole different process.  That is getting so Connected to one (or more) Shards that the investiture overloads reality and you Ascend to a whole other state of existence that exists in all three realms.   Navani was Tuning a small sample of Physical realm Light from one wavelength to another using tools and external controls; Sazed was himself becoming so over-Invested that he broke down most of the boundaries between realms and things like that.  

That being said, it's not without downsides, and Sazed has said it takes constant effort to hold them together.  Per WOB he also did not immediately Merge the shards into a stable middle thing (if "War" can be called "stable"); they've started to bleed into each other still fight each other. 

[+Invocation]

The end of Hero of Ages was a much different situation than what Raboniel and Navani were working with. For one thing, Scadrial was created entirely from the power of those two Shards, rather than the Shards descending upon the planet after Adonalsium was Shattered, so every inhabitant of Scadrial has a bit of both Ruin and Preservation inside them already in a way that the average Rosharan doesn't. For another, both of the holders of the Scadrian Shards were dead when Sazed took them up, so there was no other being with a reigning control over their Investiture. 
Also, have you read Era 2?

[Sky Breaker]

My personal theory is that the reason that both tower light and war light need two people is because the power of honor is really the power of connection and bonds as the stormfather says in OB I think or maybe RoW. And as Alek points out you can’t just tap connection to nothing you have to connect to something. so I think it might require two connected people to make warlight. Side note Eshonia hears the rhythm of war as she dies, relain hears it when he swears he’s close to becoming a radiant, venli hears it at some point, and venli hears the cultivation and odium mix when she’s practicing. So I don’t think it actually requires two people I just think that since neither of them can actually see balance between honor and odium they need each other. And I think something similar happened to the sibling and the reason she couldn’t make towerlight is because she isn’t willing to make oaths so she lost enough intent that she couldn’t make light. I know she lost some of the ability to do that after BAD was imprisoned. Anyway she could make towerlight for a while between bondsmiths.