The Ascdendant (our social mask that we wear in a social situation, until we are comfortable) .. this is someone who walks into a room and hangs back .. not participating, but observing. UNTIL they feel comfortable. And if they never achieve a comfort level, they remain holding back in that situation.
Others may notice they are watching, and feel threatened. Others may see their cool outer composure, and thing they have strength and confidence. Others may see their non-participation and think they are snobs.
Mars is our desire nature . .how we feel ANY desire we have, and how we react to our desires. So it describes things like taking action, having (or not having) initiative. Assertion, aggressiveness. How we react when we aren't getting our way .. anger.
Mars IN Scorpio will have intense desires, and tend to take intense action to get what they want.
BUT what OTHER aspects do planets make TO Mars? Squares and oppositions to Mars will bring out the pushy, manipulative, forceful side of the Scorpio style. Sextiles and trines to Mars will bring out the positive side of the Scorpio style, giving them the depth and courage to face their own desires and work WITH their desire-nature and transform it .. rather than trying to force others to do what they want.
We ALWAYS look FIRST at how the planet is aspected, because that indicates how to interpret the style of the Sign for that planet/need.
If Mars is conjunct the Ascendant, then their Mars need/nature/behavior is part of their social mask. Others will clearly SEE this side of the person.
Pluto is our personal power and how we use it. In Scorpio, this will be intense. But here, whether or not this is an intensity directed at others OR an intensity for inner growth .. depends on the other aspects made to Pluto.
Pluto conjunct Mars only intensifies the intensity of desire and using power, and the tendency WILL be to use it negatively, unless:
(1) the person has matured and mastered this tendency
(2) there are a LOT of harmonious aspects (sextiles, trines) to help the person mature and master this intensity.
And with both Mars and Pluto being conjunct the Ascendant, these two parts of their real personality (planets) are also part of what they show in social situations (their Ascendant/mask).
Understand that the only thing we see in a natal chart are tendencies that will become the person UNLESS the person changes and grows. Astrology does not control us. Furthermore, since we CAN change, it cannot accurately predict if someone has changed or not.