Having a personal God AFTER attaining Nirvikalpa Samadhi is no longer an impediment for Advaitic realization. But his devotion to Kali was preventing Ramakrishna from attaining Nirguna Brahman and thats why his Guru asked him to go beyond Kali.
Totapuri asked the disciple to withdraw his mind from all objects of the relative world, including the gods and goddesses, and to concentrate on the Absolute. But the task was not easy even for Sri Ramakrishna. He found it impossible to take his mind beyond Kali, the Divine Mother of the Universe. "After the initiation", Sri Ramakrishna once said, describing the event, "Nangta began to teach me the various conclusions of the Advaita Vedanta and asked me to withdraw the mind completely from all objects and dive deep into the Atman. But in spite of all my attempts I could not altogether cross the realm of name and form and bring my mind to the unconditioned state. I had no difficulty in taking the mind from all the objects of the world. But the radiant and too familiar figure of the Blissful Mother, the Embodiment of the essence of Pure Consciousness, appeared before me as a living reality. Her bewitching smile prevented me from passing into the Great Beyond. Again and again I tried, but She stood in my way every time. In despair I said to Nangta: 'It is hopeless. I cannot raise my mind to the unconditioned state and come face to face with Atman.' He grew excited and sharply said: 'What? You can't do it? But you have to.' He cast his eyes around. Finding a piece of glass he took it up and stuck it between my eyebrows. 'Concentrate the mind on this point!' he thundered. Then with stern determination I again sat to meditate. As soon as the gracious form of the Divine Mother appeared before me, I used my discrimination as a sword and with it clove Her in two. The last barrier fell. My spirit at once soared beyond the relative plane and I lost myself in samadhi."
In addition to teaching Ramakrishna, he also learnt from him:
Sri Ramakrishna remained completely absorbed in samadhi for three days. "Is it really true?" Totapuri cried out in astonishment. "Is it possible that he has attained in a single day what it took me forty years of strenuous practice to achieve? Great God! It is nothing short of a miracle!" With the help of Totapuri, Sri Ramakrishna's mind finally came down to the relative plane.
Totapuri, a monk of the most orthodox type, never stayed at a place more than three days. But he remained at Dakshineswar eleven months. He too had something to learn.
Totapuri had no idea of the struggles of ordinary men in the toils of passion and desire. Having maintained all through life the guilelessness of a child, he laughed at the idea of a man's being led astray by the senses. He was convinced that the world was maya and had only to be denounced to vanish for ever. A born non-dualist, he had no faith in a Personal God. He did not believe in the terrible aspect of Kali, much less in Her benign aspect. Music and the chanting of God's holy name were to him only so much nonsense. He ridiculed the spending of emotion on the worship of a Personal God.