Mula Nakshatra: The Classical Character of the Lunar Mansion
What a nakshatra is, classically
In classical Jyotiṣa the 27 nakshatras (lunar mansions) are 13°20′ arcs of the zodiac through which the Moon travels — the oldest layer of the tradition. Each nakshatra is described by a presiding deity, a symbol, and a ruling planet whose Vimśottarī daśā (planetary period) it opens, and the tradition reads the Moon's nakshatra at birth as an especially telling marker of temperament and mind. This is doctrine about a placement, not a forecast about any individual.
What the tradition associates with Mula
The tradition places Mula under the presiding deity Nirṛti (dissolution) / Kālī, with the symbol of a tied bunch of roots. Its Vimśottarī daśā lord is Ketu, so the tradition treats Ketu's significations as colouring the mind and life-themes this nakshatra is associated with. Classically it is a Rākṣasa (fierce) nakshatra with the Dog as its yoni (the animal symbol used in classical compatibility matching). Taken together, the texts associate Mula with getting to the root — inquiry, dissolution, and radical foundations. These are tendencies the tradition describes, not fixed traits, and never a prediction.
How to read this
Treat a nakshatra as one classical layer, not a verdict. The tradition reads a nakshatra together with which planet actually sits in it, the sign and house it falls in, the running Vimśottarī daśā, and the whole rest of the chart — which is exactly why a generic nakshatra description can only go so far, and your own chart, with your real Moon-nakshatra and the planets in it, says far more.