It's That Reincarnated-as-a-Virus Story Vol. 3 (Kodansha, 2022)

Having taken over the body of a hobgoblin, our protagonist is now pretending to be a human adventurer. He and Elena had just joined forces and were working hard as a party when, suddenly, Elena is kidnapped by who-knows-what! The protagonist loses himself in rage and races after to save her, but then...?! Join us in this story of two adventurers who explore dungeons and defeat all manner of monsters, in volume three of the series!!