from your own vesion what the most important skill the employer taking care of while interviewing you ?

Interview will be the main tool to collect the necessary facts, both structured and semi-structured from which employer can collect the clear view of the employee.
It will be easier to find how the employee looks like and how he/she is confident in his/her presentation so an interview plays a vital role to select an employee.

Employers want to know: Is the person able to communicate efficiently and succinctly? Does he or she appear prepared and informed about the position, which might indicate the candidate's general approach to preparing for important meetings? Is the candidate someone who would be pleasant to have in the office, or does he or she bring a negative attitude?

I think the two most important characteristics are the charm and charisma.
One has to be charming and charismatic in order to "sell" himself / herself to the potential employer.
It is about presenting yourself as a high quality product rather then just generically answering the asked questions.
Other then that, employers highly value a person who is honest and knowledgeable within his / her professional occupation.

professionalism with the focus on honesty, consistency and communication of leadership combined with performance and challenges

Your poise under pressure.

confidence, proper eye contact communication

Body language and confidence to answer all the questions asked by your employer.

"CONFIDENCE"

Confidence in your appearance and words? That's one skill which can be measured directly.

Ability to be maintain and accurate

The ability to communicate and persuasion