There is a noun - a forge. There is a verb - to forge. The verb means to create/develop/make; and if we are talking about making metal objects they are made in a forge (smithy). In the olden days every village would have a forge (where swords, ploughs(plows), and horseshoes were made. You can forge many things, including friendships and alliances! It suggests hard work has been done to create these friendships. A sky forger would be some kind of god: a being who could create the sky. It must be hard work, and take a long time, to create the sky. The verb TO FORGE and the noun FORGER are good choices.

The word “Skyforger” is a personification of the ancient Latvian pagan god of the Sky. His name in Latvian is Pērkons and ancient tribes believed that he was master of the whole universe; the one who makes thunder and sends down lightning to destroy evil doers