Chiron is a title given to the wisest centaur in any given centaur herd. It translates roughly to adviser, and it is the role of the chiron to council the stallion in matters of faith, prophecy, law and order. The chiron is the only member of the centaur herd allowed to outwardly practise magic other than the respected astrology, which is a great honour for the centaurs are naturally adverse to magic. Chirons are generally physically weak, and also somewhat loathed for their blatant use of magic, and therefore are in need of the constant protection of the stallion in order to remain safe and whole.
A good chiron councils their stallion well, or else the stallion may wish to appoint a new chiron- and such an act can only happen with the old chiron slain. Similarly however, a stallion must do their duty to the chiron, or else the chiron may favour a new candidate for stallion, and aid in the upheaval of the old. A strong herd has the perfect symbiosis between stallion and chiron, and together they search to improve their standing in the world and keep their denizens happy.