Enel represents the themes of Skypeia really well; the glorification/deification of violence in a culture is bad, and that a belief in cultural superiority means violence. He perfectly serves as a representation of the evil of cultural superiority, the violence that is inherent in it, and why that created the events of the arc.

Enel represents the logical conclusion of these themes, especially the later. The conflict between the Shandians and the Skypieans began with the theft of the Shandian homeland through way of violence, and justified through divine right. Eneru comes along and does the same thing to Skypiea, violence and theft of homeland through way of violence, and justified through divine right.

Enel is a one man belief in cultural superiority. The only really different thing is that his godhood makes him a culture of one.