Depends on what event it is,
For resurrection , the event to detect it is 'Unit - A Unit starts the effect of an ability'
and the condition would be 'Resurrection' , can be used for Ankhs and Reincarnation (Orc ability)
For altars, it might be a unit is being trained ..? and the condition might be (Unit being trained equal to 'Your hero') ( Or unit type equal to 'your hero's unit-type' )
For triggers, it can be done in many ways, using booleans for example, for example, the trigger of reviving ( Hero - Revive Hero at point ) , afterwards make boolean ( HeroRevived = True )... And make another trigger using the event (' Time - Every 0.1 seconds of the game ) , the condition would be ( HeroRevived = True ) , Actions would be ( Trigger - Turn off this trigger , and run your health bar trigger ) ,
You can keep it on tho
Good luck