What is the most important quality a person needs to be a great leader?

To be trustworthy.

diligence, intergrity and discipline

Trust and caring leader.

Integrity, trustworthy, decision making skill,good listener, ability to carry people along, honourable, accountability etc.

A leader with integrity builds trust, and trust is the foundation of everything else: respect, teamwork, loyalty, and influence.

To be trusted

A leader must have several qualities of being a leader. Each quality fits a particular situation. Example being courageous is required among the soldiers in war operations. Trustworthiness, to who will handle finances. Being approachable to a teacher or counsellor.