Shpoopshmoop

Alright I don't know if I missed something or what but I've been left really confused since I read Oathbringer the first time. So its been stated that first the heralds received their powers through the oathpact with the almighty, which happens after humans switch from odium to almighty and spren learned from that how to form the nahel bonds that allowed people to become radiant and surgebind. According to the Eila Stele in chapter 111 in OB the radiants who at the time were of odium and therefore couldn't bond to spren (b/c pre oathpact) somehow destroyed their world and came to roshar and took it over? I feel like I'm missing something because it hasn't been brought up anywhere I can see despite being a major plothole.