This is an uncommon case, and the archangel didn't know that his act of purifying the charm ability would still push himself into the trap.
The archangel reacted fast and wanted to go back to the second king's mind so that he wouldn't disappear, but Asmodeus didn't let him go so easily.
At the same time, the other three demon lords who told Asmodeus to kill the archangel also saw the opportunity and jointly helped him prevent the archangel from returning to his medium!
All the people involved in this assassination reacted too fast.
So fast that the other archangels didn't have time to stop the other demon lords and Archangel Raphael's consciousness was already trapped outside of his medium.
The other demon lords used various tricks to lock the space around Archangel Raphael's consciousness, holding back the archangel so that he couldn't return to his medium for a few seconds.