Some sources say Ronové acts as a psychopomp–a spirit who escorts souls to the afterlife, but only the souls of old, decrepit people.
Which would really scare those people, since he looks like a monster.
When summoned (though supposedly not by anyone over the age of sixty), he teaches rhetoric (how to persuade others to your point of view) and other languages. He can give his master other spirits as servants. He can get both your friends and foes to do things for you.