Mercury, when placed in the 5th house of Leo ascendant, can give a mixed set of results. The Mercury is placed in the enemy sign state, which might bring some challenges and hindrances in its functioning.
As Mercury is the lord of the 2nd house and 11th house, it takes care of matters related to wealth, values, speech, and communication. The native might have an intelligent and analytical mindset which can help them gain wealth through their communication skills. They may also be good at negotiations and making deals. However, there could be some challenges with regards to their family values or conflicts with siblings.
Mercury is a natural karaka or signification for the 4th house and 10th house. The placement of mercury in this house can bring success to the native through education or career-related matters. The person may have a creative side to them that can be utilized in professions such as writing, speaking, acting or performing arts. As Mercury's aspect falls on the 11th house from the fifth where it sits - gains are also possible if they work hard for it.
While this position has its share of blessings and setbacks; one thing that stands out is how placement affects relationships with children. With Mercury placed here while being aspected by Mars from Aquarius - we may find these natives having a strong connection with their children but could face competitions over small things between them time and again.
Additionally, since the mercury has an aspect on the eleventh house - this placement could bring substantial gains that come from networking abilities and socializing which can result in establishing helpful contacts who would invite opportunity to participate in reasonable acts/events.
However, despite these positives Venus' weak placement will cause some harmful effects especially when it comes down to financial matters considering Venus' relationship with expenditure/excess/money matters; these weak effects could come into the limelight as unexpected expenses likely.
In free time one can study astrology and its aspects, join chat groups or any other activities which arouse interest. The preference given here to the good will help one appreciate more the blessings of life and resist being lost in difficulties distracted by negativity.
In conclusion, a Mercury placed in the 5th house for Leo ascendant can bring both advantages and challenges. However, with an analytical mind and communication skills, the native can overcome any obstacles and achieve success through education or career. With positive networking abilities plus socializing skills that brings gains - this placement could establish further helpful contacts who would invite opportunities initiating possible major breakthroughs soon after if utilized to their maximum capacity. Remember to avoid overspending as an area where Venus' weakness lies as it could result in eventual harm then regain lost footing steadily.