Ongoing Effect
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, King of the Realm's passive ability is an ongoing effect that gives you control of all mortals. Gnome Hollows' passive ability is an ongoing effect that prevents units with 3 or more power from entering. Quagmire'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.
If there are multiple ongoing effects, the game will apply all of them before checking to see if any minions died.
For example, you have a Bosk Troll that has taken 1 damage this turn. Then, you move it to a location that is nearby both Wicked Witch and your House Arn Bannerman. Both the Witch and the Bannerman generate ongoing effects with their passive abilities.
If the game applied the -2 power from the Witch first and then immediately checked for minions dying, the Bosk Troll would die, even though it shouldn't due to the House Arn Bannerman.
Therefore, between each event on the storyline, the game applies all ongoing effects before checking for minions dying.
