Future sight in the Cosmere is something I have been dying to know about for YEARS.
There are multiple methods of achieving it with Shards being far above everybody else, and some individual shards being better than others. Wyrn seems to do something a little differently however.
Futuresight seems to work that the further you look into the future/spiritual realm the more possibilities there are. Which is very realistic and the inclusion of if you get two people looking into the future it becomes hazier or murkier.
Atium on the other hand is a brief glimpse into the future ie a few seconds. I think that is it’s edge, it is small In scale. Nothing like what Renarin does which seems far broader and deeper and becomes harder to interpret.
When two Atium users come face to face it’s cancelled out and follows the same principle unless has one more atium. Renarin seems to be seeing things weeks or months in advance so it becomes more vague.