The party is fighting a narzugon. In addition to the three attacks per round that it makes, its statblock states that it also uses its Terrifying Command ability:
Each creature within 60 feet of the narzugon that isn’t a Fiend must succeed on a DC 17 Charisma saving throw or become frightened of the narzugon for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. A creature that makes a successful saving throw is immune to this narzugon’s Terrifying Command for 24 hours.
The party has a Twilight Cleric who has activated their Channel Divinity: Twilight Sanctuary ability which states:
Whenever a creature (including you) ends its turn in the sphere, you can grant that creature one of these benefits:
- You grant it temporary hit points equal to 1d6 plus your cleric level.
- You end one effect on it causing it to be charmed or frightened.
Only two of the party members made their initial saves, leaving the other four with the frightened condition. It is clear to me that the Twilight Cleric can end this condition on each of these four at the end of their turns if the cleric chooses.
What's not clear, is if this method of ending the condition counts as a successful save in terms of each player becoming immune to the narzugon's Terrifying Command.
The reason that this distinction is important is because the narzugon can re-apply the frightened condition on each of its turns (assuming the party fails their saves), and this condition will persist through each player's turn until it is removed at the end of their turn by Twilight Sanctuary - basically negating the benefits of Sanctuary.
Is removing the frightened condition the same as making a successful saving throw when it comes to immunity from the effect?