Learn English – Word or phrase for one expecting gratitude and who often boasts about his generosity

In terms of giving a morale boost, one could refer to an inspirational or totemic leader. As a noun, a leader could simply be described as an inspiration, although this is a broad term that can refer to any inspiration. If someone gains power/morale from being supported by their troop, they can be said to have been rallied by the troop, and in return they can rally their troop. As you suggested, the leader could also be motivated by their troops, or motivate their troops.

In a civilian as opposed to a military context, there are all sorts of positive adjectives one might wish to assign a good leader who boosts their people's morale. Some of these could be competent, charismatic, and charming. A great leader may become famous and/or celebrated.

You might say "one woman man", meaning for that particular man, there was only one woman. Usage: He was a one woman man, and after his wife died, he never remarried.

Equally you could say, "one man woman", meaning for that particular woman, there was only one man. Usage: She was a one man woman who remained single after her love married another.

In "one woman man", the phrase "one woman" acts as an adjective to describe the man.

In English I am unaware of a single word to convey the meaning you require, other than monogamous.

Additionally, in English, monogamous is not gender specific. A woman can be equally as monogamous as a man. Usage: Both Bill and Mary were monogamous. Luckily they were married to each other.