How malefic and benefic they are in different ascendants , can be studied in the following way The lord of Trikon Bhava in a horoscope is always benefic.Trikon Bhava is formed with the three houses in the horoscope.
All the planets in astrology gives results according to their condition, conjuction, and aspect. If the planet is in benefic house such as Trikon Bhava , Kendra Bhava ,then it gives good results or is the lord of any