The Moon isn't combust, as your title suggests; it's in the Via Combusta. 'Combust' means conjoined with the Sun; combustion occurs when a planet is within 8 degrees of the Sun and the planet's energies are 'burned up'. If it's within 17 degrees, it's 'Under the Sunbeams', a place of debilitation. Via Combusta (the Burning Way) is between 15 degrees Libra and 15 degrees Scorpio, and describes an unstable and anxious state; this particularly pertains to the Moon. The moon in this chart is also in fall in Scorpio, however, so is particularly debilitated.
Mars does indeed interfere and there is no getting around that. Mars can represent many things: another person whom the Mercury person meets in the meantime; it can mean an argument, etc. depending on the context.
The bigger problem is that the Moon, in fall, has separated from Mercury and translates the square to Mars. This means a fairly clear 'No'.
We have to think of the moon as the engine of a car; if the engine is powerful it can carry the vehicle forward with ease, even if that vehicle is loaded up with a lot of extra weight. Think of a semi: it pulls a huge amount of weight behind it on the trailer. Now, try hitching that trailer to, say, a 1987 Honda Civic. Will it be able to pull all that weight? Heck no.
A Moon in dignity is like that semi: because it is strong it can pull a lot of extra 'stuff' along and move the chart along, even if there are difficult aspects such as squares. A Moon in fall is extremely weak; like that old Honda engine, it can't manage to pull anything behind it, most especially the difficult square aspect...particularly
because there is no reception between the Moon and Mercury.
When asking questions about soulmates and whatnot, ignore the 4th house *(end of the matter), because that particular house is only useful in questions where the outcome is uncertain and depends upon a third party, such as in legal trials. In romance questions, what you really need - what you ONLY need, in truth - is a coming together of the 1st and 7th significators, or a healthy translation of light between them, via another planet...healthy meaning with positive reception.
Unfortunately in this chart, there is no testimony that this person is a soulmate, let alone that they will have much of a relationship.