Harmony has the standard powers and vulnerabilities of a vampire: superhuman strength, speed, reflexes, and durability, along with virtual immortality. She is vulnerable to holy items and sunlight, and must regularly feed on mammal blood to maintain her vitality. Harmony cannot enter the home of a living human without being invited by someone who lives there first. Also, in the episode "Conviction", she claimed that she could "type like a superhero." Interestingly a similar ability was shown by Buffy in season six episode "Gone".