They say Gu was born with a human body and a blade as a head. This perfectly portrays his role as the god of iron and war. The two things are related; iron ore is used to make weapons for war, among other things.
A title like the Vodun of War denotes a spirit who is angry or out for destruction or chaos, but that’s false. A god of war is not necessarily there to sow conflict and division. Still, they are there to bestow victory, wisdom, and protection in battle when facing your enemies. Immediately we run into trouble. Why does he favor one side over another? These reasons are privy to him but always in the interest of ultimate fairness.
The Fon worshiped Gu to bring them success in war and protect them in conflicts, protect their wealth and community. At the end of the day, that is what a god of war is supposed to do—a more accurate title would-be protector of communities and nations.
There is also a building role. Iron is a symbol for minerals that can be mined and used to service those pursuits that strengthen and protect a nation. It stands for resources that can be used as weapons and defense. You can substitute nations with family, community, town, tradition, culture, city, or whatever you think is worthy of protection or strengthening. The Vodun of War resides over these matters. It dispenses favor, resources, wisdom, and advantage according to its divine wisdom and foresight.
Source: Vodun. Monique Joiner Siedlak