I was taught the Kleem mantra by Swami Rama of the Himalayas in 1974 (I think). He told me that it means:
Peace, Power, Perfection
Love, Light, Life
Happiness, Healthiness, Holiness
I meditated with that mantra for many years and, although I no longer use it (for the last 12 years I have done a Buddhist practice called Falun Gong that uses no mantras), I can't imagine any evil coming from it if you use it correctly. I would say it is a misuse of any mantra to practice it trying to achieve some worldly goal. The purpose of meditating (with or without a mantra) is to free ourselves of attachments to worldly goals. One who meditates with an aim to achieving a worldly goal is engaging in an evil practice. Harm is likely to result - probably not to others but to oneself - but it is coming from the desires and pursuits of the practitioner - not the mantra.
