This is a complex topic and one we take seriously.
Every single person has an Ascended Master team, not just one Ascended Master, but five Ascended Masters. The Masters call it the Five Ray team.
There are eight rays of incarnation and we are all are born with five of these rays.
We incarnate on these specific five rays for the lessons we are here to learn in this lifetime. The Ascended Masters are all on one of these eight rays, with specialties within each ray.
The five rays are: Ascension ray, Life ray, Mental body ray, Emotional body ray, and Physical body ray. With your five rays you will have an Ascension ray Master, a Life ray Master, a Mental body ray Master, an Emotional body ray Master, and a Physical body ray Master, respectively.
An Ascended Master is assigned to each of your five rays according to your life and soul lessons. The Masters are assigned within the first year of birth, though they will likely change again at age 14 when all your past life karma is uploaded into your chakras. For example the rays and Masters that were assigned to me after age 14 looked like this 1-1-3-1-1. So I had the first ray for my ascension, life, emotional and physical rays and the third ray for my mental body ray. My Master team was El Morya - El Morya- Kuan Yin - El Morya - Sitatapatra. I had El Morya for my ascension, life and emotional body lessons. Kuan Yin was my mental body ray Master and Sitatapatra was my physical body first ray Master.
This team is with you for life or until you pass the 6th initiation. When you open your heart to them they can be more effective.
We supply the Ascension Master and Life Master and their rays as part of the free Ascension teaching modules. These are the most important rays and they form a hint of your soul purpose, your life’s lessons, and your life path. These rays will have an influence on the way you think about the world, how you feel about the world, and how you act in the world. Knowing your these two Masters and Rays will give you insight into Self, helping you know and recognise yourself in a deeper and more forgiving way, knowing much of who you are is created for you and this life’s lessons.
If you want to know more about the Ascended Masters, this internal page "The Ascended Masters" is a good starting page.
If you want to learn more about the Rays, here are two internal links for you to follow: The Eight Rays of Incarnation and The Eight Rays of Incarnation - Facts.