The natural step from Artemis would be to her twin brother, Apollo.
Artemis - Goddess of the Hunt, Forests and Hills, the Moon, Archery
Apollo - God of music, poetry, art, oracles, archery, plague, medicine, sun, light and knowledge
Zeus - God of the sky, lightning, thunder, law, order, justice
It's a tough choice, the "Zeus Rocket Launcher" would be super big powerful so its like the father of the artemis which would make sense, but I like the idea of the artemis having a twin brother rocket launcher. Hmmmmmm.