Answer the question at the end by quoting:

Drusilla, or Dru, is a fictional character created by Joss Whedon and David Greenwalt for the American television series, Buffy the Vampire Slayer and Angel. The character is portrayed by American actress Juliet Landau. Drusilla is introduced alongside her lover Spike (James Marsters) in the second season of Buffy the Vampire Slayer to serve as new antagonists to the series' heroine, vampire Slayer Buffy Summers (Sarah Michelle Gellar) and alongside Darla (Julie Benz) and Wolfram & Hart as the main antagonist of the second season of Angel. In contrast to the series' previous central villain, the ancient and ceremonious Master (Mark Metcalf), Spike and Dru were introduced as a more unconventional but equally dangerous pair of vampires.
Drusilla has all the standard powers and vulnerabilities of a vampire, plus minor psychic abilities. She is immortal, regenerates damage, drains human blood to survive, and is stronger than most humans. Drusilla's technique in combat, although awkward-looking, has allowed her to briefly hold her own in a fight against Angel (in "Reunion") and Spike (in "Becoming, Part Two"), along with besting Kendra the Vampire Slayer (in "Becoming, Part One") before using the hypnosis technique and then killing her. It was also in this fight with Kendra that Drusilla showed that her fingernails are sharper than one would normally expect, as she uses them to slit Kendra's throat. Darla had demonstrated a similar technique when she sired Angel; whether this is due to vampiric abilities or physical manipulation of nails is unclear. Drusilla is also a seer with minor psychic abilities. However, since she had these before becoming a vampire their source and cause are unknown. She receives vivid visions that contain possible glimpses of the future, and can also see into people's minds and project false imagery into them (e.g. in "Becoming, Part Two", when she convinces Giles that she is really Jenny Calendar). She is also capable of hypnotizing people, which she does by catching their gazes, pointing her fingers towards her victim's eyes and then to her own, whispering to them ("Be in my eyes, Be in me"). Drusilla uses this technique to murder Kendra in the episode "Becoming, Part One". The Master uses a similar skill to paralyze Buffy in "Prophecy Girl". Like all vampires, she is vulnerable to holy items and sunlight, can be killed by decapitation or a stake to the heart, and cannot enter the home of a living human without first being invited by someone who lives there.

what are her powers used for?

It was also in this fight with Kendra that Drusilla showed that her fingernails are sharper than one would normally expect, as she uses them to slit Kendra's throat.

Answer the question at the end by quoting:

Hackett was born in Brooklyn, New York to Anna (nee Geller) and Philip Hacker, an upholsterer and part-time inventor. He grew up on 54th and 14th Ave in Borough Park, Brooklyn, across from Public School 103 (now a yeshiva). He graduated from New Utrecht High School in 1942.
Hackett starred as the title character on NBC-TV's Stanley, a 1956-57 situation comedy which ran for 19 weeks on Monday evenings at 8:30 pm EST. The half-hour series also featured a young Carol Burnett and the voice of Paul Lynde. The Max Liebman produced program aired live before a studio audience and was one of the last sitcoms from New York to do so. Stanley revolved around the adventures of the titular character (Hackett) as the operator of a newsstand in a posh New York City hotel. On September 30, 1960, he appeared as himself in an episode of NBC's short-lived crime drama Dan Raven, starring Skip Homeier, set on the Sunset Strip of West Hollywood. After starring on Broadway in I Had a Ball, Hackett appeared opposite Robert Preston in the film adaptation of The Music Man (1962). In It's a Mad, Mad, Mad, Mad World (1963), Hackett was paired with Mickey Rooney, with whom he had also recently made Everything's Ducky (1961), in which they played two sailors who smuggle a talking duck aboard a Navy ship. Children became familiar with him as lovable hippie auto mechanic Tennessee Steinmetz in Disney's The Love Bug (1969). He appeared many times on the game show Hollywood Squares in the late 1960s. In one episode, Hackett was asked which was the country with the highest ratio of doctors to populace; he answered Israel, or in his words, "The country with the most Jews." Despite the audience roaring with laughter (and Hackett's own belief that the actual answer was Sweden), the answer turned out to be correct. Hackett's regular guest shots on Jack Paar's Tonight Show in the early 1960s were rewarded with a coveted appearance on Paar's final Tonight program on March 29, 1962.

Any other significant things he worked on?
coveted appearance on Paar's final Tonight program on March 29, 1962.