The idea for this theory started when a friend of mine told me that Nightblood was eventually Szeth's Shardblade. I saw one problem with this, after finishing Warbreaker. Nightblood needs to feed off of BioChroma. This got me thinking. My theory is that BioChroma and Stormlight are very similar or the same, but are effected by the world, type of investiture, or person. An awakener might be able to suck in stormlight, converting it to BioChroma. On the other hand, BioChroma and Stormlight might not be similar enough for persons of investiture to absorb these various powers, but similar enough to power Nightblood. I couldn't find any other strings relating to this, and you can feel free to smash my theory to pieces if necessary. Also, If anyone finds a string relating to this, please tell me.
Thanks,
T8