So we know that Adonalsium visited Roshar before the Shattering, and there have been Spren there since there. After the Shattering, when Cultivation and Honor settled there, the spren changed somehow? Maybe there's more of them, not sure about that.
At some point Odium visited, and Desolations started happening, So Heralds were (created?/chosen?) After some time, spren began to imitate Honorblades and Knight Radiants came into existence. I think the Shattering came next (and betrayl of Oathpact? not sure of the sequence) Then the desolations were over and recorded histrory started. Then The Recreance happened.
Is my timeline right?
Also how were emotionspren (which are basically spren of Honor) changed by the Shattering?
Also, are Knights Radiant immortal? Syl says that practically all of the thinking spren were killed by the Recreance. I would assume that if a Radiant dies, the spren becomes unbonded but isn't killed. And the spren itself may decide whether to bond again or not. So that means if almost all thinking spren were killed, then almost all thinking spren were bonded, and I would assume some spren may retire if their radiant dies normally, especially as Desolations had stopped. Also, Stormlight heals you to the way you see yourself, so if Radiants see themselves the way they are, or think of themselves as yound, they wouldn't age.