Who are the 19 Siddhas? 

Everything in nature is ensouled: animals, plants, people, trees, planets, etc. The consciousness of every living being vibrates on a certain frequency level. This frequency level determines the reality from which a being lives and creates its reality. The higher the frequency level of consciousness, the more unconditional love, pure intentions, intuition, selflessness, forgiveness, inner peace and joy a being has realized and the more it lives in harmony with its true destiny and the laws of nature and the closer it is to the divine source. The lower the frequency level of consciousness is, the more the consciousness is permeated with conditional love, self-centered motives, attachments to emotions and inner hurts. To raise the frequency level, it takes a process of transformation and purification of consciousness, of all aspects that lower the frequency. 
When the soul leaves the body, after the transition to the spiritual dimensions, it enters those levels in the subtle worlds that resonate with its soul frequency. Just as there are different levels of consciousness on earth, so there are also in the spiritual worlds. What is special on Earth is that all beings, regardless of their level of consciousness, are given the opportunity to change their frequency and grow in the direction of more unconditional love, forgiveness, etc. This raises the level of the soul in the subtle worlds, which influences what levels of experience we will attract in this world, but also on the other side after our transition. 
Since the whole universe is ensouled and animated, there are entities not only on Earth, but also on the subtle levels, which are not visible to most people, that work and operate from different frequency levels for the good of Earth and humanity. This is especially the case now in the time of transition. So, among others, there are many angels, archangels, ascended masters and many other entities from other light-filled levels that support the current transformation process. In the coming years we will have more contact with these planes and communicate with them in a natural way.