Gandalf (Olorin) learned pity and wisdom from her and he is considered one of her most well-known followers. That is important an contribution, even though as you say, it is technically an indirect effect.

That being said, with the exception of Tulkas and Orome (with Orome being acknowledged of the greatest at armed combat and Tulkas the greatest at wrestling and physical force), even the Valar did not really go forth in battle or demonstrate overbearing battle prowess. Manwe, their chief, for example, went to war against Melkor, but could not overcome him alone. It seems like their nature of battle has less to do with overpowering an opponent with might, and more to do with understanding an element of an opponent and being able to draw upon greater cosmic forces to neutralize it. Varda, for example, struck the first blow against Melkor not by hurling a javelin at him, but by creating the stars which always drove back Melkors' monsters and gave courage to the Elves and Men.