Is the Flame Wisp spell’s damage added to the Strike’s damage, or dealt as a separate damage instance?

Separate instance

Flame wisp deals damage via a 1 minute duration spell. The character who cast flame wisp is causing damage with the spell, with the only association to the Strike being that the Strike “triggers” the damaging effect. No language in flame wisp is nor is synonymous with “added to” in regards to the Strike’s damage (in fact, the Strike doesn’t have to successfully damage the creature at all).

This has benefits and limitations; status bonuses to damage applies separately, but so does Resistance.