ally — A country's ally is another country that has an agreement to support it, especially in war.
friend — a person attached to another by feelings of affection or personal regard.
assistant — Assistant is used in front of titles or jobs to indicate a slightly lower rank. For example, an assistant director is one rank lower than a director in an organization.
backer — A backer is someone who helps or supports a project, organization, or person, often by giving or lending money.
helper — a person or thing that helps or gives assistance, support, etc.
