Objective: We employed the network methodology to explore the connections between the Dark Triad (DT) traits with Mental Toughness (MT) and the degree to which they account for perceived stress beyond the Big Five (B5). Method: Network analyses were undertaken to explore connections between the DT, MT and perceived stress, independently in two samples, and in the combined dataset; and whether B5 factors are responsible for the connections that emerged in the original network. Results: DT and MT traits improved the prediction of perceived stress above the B5. Furthermore, narcissism occupied a strategic position in the network acting as a bridge between prosocial and “dark” sides of personality. The pattern of network connections could not be explained by B5 traits alone. Conclusions: The results suggest that there is more to personality than what can be captured by the B5 and that broadening the domain of personality beyond the B5 can improve the prediction of important outcomes, such as perceived stress. Narcissism is a unique trait and studying its connection with MT may be the key to moving forward from a dichotomous way of perceiving personality traits, as beneficial or malevolent, to focusing on a dynamic continuum of personality.