Let’s look at important things here –
Mars - Mars represents our will power, courage, ability to take actions, aggressive nature, anger, our fighting ability, brother, male friends, a boy friend for a girl, a soldier, an athlete and real estate etc.
Ashlesha - Ashlesha represents our insecurities and weaknesses as a human being. It is a nakshatra of clinging on to someone or something. It also represents psychological issues. For more information on Ashlesha Nakshatra, please check this link - https://www.astrosaxena.com/Ashlnaksh.
Cancer - As Ashlesha is a part of Cancer, Cancer sign and its representations become important. Cancer is 4th sign of Zodiac Belt, hence it represents the things represented by 4th house like Mother, Mother's Care, Emotions, Taking Care of Others and Nourishment etc. Cancer is consisted of 2 and half Nakshatras namely Punarvasu, Pushyami and Ashlesha. Cancer's lord is Moon, which again represents almost same things which Cancer and 4th house represents.
Moon - As Moon rules Cancer, Moon's position and dignity is important to know about the overall functioning of any planet in Ashlesha/Cancer.
Mercury - As Ashlesha is ruled by Mercury, Mercury's position and dignity will also have an important role in functioning and results of any planet in Ashlesha.
Houses Involved – Also, we can’t afford to forget the houses involved as a planet can be ruling different houses and sitting in different house for every person as per ascendant and planet’s position. To know overall affect, we have to consider the houses involved as those areas of life are being impacted.
Interpretation of Mars in Ashlesha Nakshatra – We can say that Mars is in a very troublesome zone when it is in nakshatra from Ardra to Ashlesha. It is because 1st of all Mars is a natural malefic planet which can bring accidents, surgeries and bloodshed. Then from Ardra onward, we are in an area of sky where all nakshatra are somewhere connected with chaos and transformative events or looking after those who are going through those events. Then not to forget that we are in Cancer sign where Mars is debilitated/weakest. And now, Mars is in Ashlesha Nakshatra which is among the troublesome nakshatra as it represents our insecurities, fear and clinging nature. So, in a way, I would consider Mars in Ashlesha/Cancer as the most troublesome position as nakshatra and sign both are not giving any support to Mars. As Mars is debilitated in Cancer, they can be fearful which can make them violent or aggressive in order to secure or safeguard themselves. And then in Ashlesha Nakshatra, their whole effort and action can be around clinging on to something or someone to feel secured or safe. Somehow I feel that this emotional insecurity can lead to psychological issues in person which actually makes it a very tough position. Main problem is that as Mars is weakest in Cancer, they don't even know if they are clinging to right person or thing. Their efforts or actions can be totally lost in wrong direction and towards wrong people.They need to learn that their inner safety or security won't come through clinging on to anyone or anything in outer world. It would come only when they perform some important tasks in their life successfully which will give them confidence that they are good enough to sustain and progress in this world. With all the nakshatra positions in Mars in Cancer, meditation is very necessary to create awareness and redirect this troublesome Mars energy in positive pursuits.
Role of Moon – Moon's placement is important to guide Mars in right direction, being Cancer's lord.
Role of Mercury - Mercury's placement is important to guide Moon in right direction, being Ashlesha lord.
Other Factors – And of course, we need to consider conjunction, aspects, house lordship, house position and dashas etc to know the exact results of Mars in Ashlesha. So, we always need to take a holistic view of chart rather than just 1 planetary position.
Conclusion – So, this is how I see Mars in Ashlesha can work in a chart.