The good and the bad!
I am not, however, convinced that many (if any) narcissistic leader is be able to temper their narcissism sufficiently to benefit from the characteristics. They would surely lack the self awareness to begin with - see table below.
Non-narcissistic leaders could of course learn to adopt these characteristics for the benefits without the donwsides.
Food for thought nonetheless.
(Click on images above to link to the source.)