Determination

adjective describing a person who is determined and resolute in their opinions and beliefs

• She is known for being a strong minded individual who always stands by her principles.
• My sister is so strong minded, she never lets anyone tell her what to do.
• Don't mess with him, he's one of the most strong minded guys I know.
• Her strong minded attitude is like a shield, protecting her from negativity.

adjective describing a person who is determined and resolute in their beliefs or actions

• She is known for being a strong-willed leader who never backs down from a challenge.
• My sister is so strong-willed, once she sets her mind on something, there's no changing it.
• That girl is seriously strong-willed, she always gets what she wants.
• His strong-willed determination was like a force of nature, unstoppable and fierce.