Ongoing effects apply continuously during their duration. If they do not have a listed duration, they apply indefinitely while the source is in the realm. For example, 's passive ability is an ongoing effect that gives you control of all mortals. ' passive ability is an ongoing effect that prevents units with 3 or more power from entering. 's genesis ability creates an ongoing effect that causes units to be Immobile while they occupy nearby sites until your next turn.
Between each event on the storyline, apply all ongoing effects. That is, the game is very regularly applying ongoing effects, both before and after each event on the storyline.
Most of the time, the application of ongoing effects is straightforward; simply apply them. If you need to resolve a complex interaction involving multiple ongoing effects and the order in which they apply is unclear, consult the following article: Ordering Ongoing Effects - The Layer System.