Assume we're a Swarmkeeper Ranger who's fighting a werewolf and attacking with a magical weapon.
Does the swarm's damage affect the werewolf?
More precisely, there are two questions:
- Is the swarm's damage technically part of an attack? If not, the werewolf's immunity wouldn't apply, right?
- Is the swarm's damage considered to be magical for the purpose to overcome resistance or immunity?
The Swarmkeeper Ranger's Gathered Swarm feature states
A swarm of intangible nature spirits has bonded itself to you and can assist you in battle. While you’re alive, the swarm remains in your space, crawling on you or flying and skittering around you within your space. [...] Once on each of your turns, you can cause the swarm to assist you in one of the following ways, immediately after you hit a creature with an attack:
- The attack’s target takes 1d6 piercing damage from the swarm. [...]
Meanwhile, the werewolf has the trait:
Damage Immunities Bludgeoning, Piercing, and Slashing from Nonmagical Attacks that aren't Silvered
As far as I understand it, the only way for the werewolf to be unaffected would be that the damage is part of the attack, but still not considered magical - even if the attack was made with a magic weapon.