The 10th Doctor

The first of the "skinny man" iterations, the Tenth Doctor projected a convivial and frivolous front to conceal the inner fury and wistful melancholy that spawned from his underlying guilt of the Last Great Time War and the additional deaths and misery that followed in his wake. Indeed, once his easy-going attitude had been overwhelmed by conflict, the Doctor's energies would shift to reveal a fiercely protective man who resolutely guarded what he held dear, and who could be viciously unforgiving to the forces that dared menace them until he was victorious.

However, he held deep respect for pacifism, and had zero tolerance towards anyone who wanted to engage in violence to resolve conflicts and disapproved of guns unless they were unquestionably a last resort. He also had vanity issues that made him attached to his current body, this attachment to his current body was so strong that he became the only incarnation of the Doctor to willingly abort one of his regenerations midway through the process itself, by way of siphoning the remaining regeneration energy that would have given him a new body into a matching bio-receptacle, allowing the Doctor to heal himself while keeping the same face after he was struck by the neutronic energy of a Dalek's gunstick.