Sol, Shiva and Svarog all have super good Awakenings, so it's just a matter of who do you use/like the most.
Odin Awakening is really lackluster, and you might as well not bother.That depends on content. In general you want to be strong enough to not use healers at all, for many things (such as Dark Ult and Dark Rag) that is rather difficult to reach - if not impossible.
I'd say get yourself Herc with her Axe and see how that goes. I kind of doubt that you're reaching -50% Def, so that really gimps your damage output, and Herc will really help with that.