Shikaree

Doesn't necessarily mean spren are not related to the radiants. My theory is something similar. The heralds created the orders of radiants. The spren could be the souls (or something of the sort) of the people who died fighting with the heralds, during any desolation. It doesn't have to be the radiants who betrayed mankind after the last desolation. (rather, it seems like the true radiants abandoned their blades and the "radiants" who did betray mankind were the unqualified people who picked them up) There are probably 10 different radiant spren, each of which corresponds to one of the 10 essences, which also corresponds to one of the 10 orders of radiants. And the dead radiant-soul-spren seek out people who would fit into their order and bond with them to give them additional powers. WoK shows two: the soulcasting spren and Kaladin's honorspren. This could also be the origins of the whole die and go fight with heralds in tranquiline halls. In reality, you die, become spren, and fight with the heralds and radiants during the next desolation. The soulcasting spren seems tied to truth. On the handy chart at the end of the book, entry number 6 conveniently associates blood with creative / honest. I think ample evidence that strongly favors some sort of connection with radiants can be found in chapter 38, when Kaladin is seeing deathspren. I'd like to think the words were chosen carefully. I do strongly agree with 5. The Knights Radiant gave up their Shardblades for some reason. Syl also has a strange hatred of Shardblades. which I hadn't thought about. I also do agree with 4. As his link with Syl grows stronger, the oaths of the Knights Radiant appear in Kaladin's mind. which I did notice. =p During the last fight Syl asks Kaladin for the words, which turns out to be the second ideal of the radiants. I believe not even Dalinar knew those words and he's been studying that stuff. He only knew the first. Edit: Oh, and of course, there are a bunch of other... regular... spren. I don't think there's enough evidence to really support any detailed theories regarding them.