This is my 0 Forma unkillable [Octavia]. This requires no Orokin Reactor, and you can still take on any mission in the star chart. This builds simply utilizes 6 mods to boost stats in all categories. I am using three of the augur mods so that when casting an ability you get shields back so that you can shield gate. If your shields are depleted and you are in danger, you can cast her 4 to get most of your shields back. I have [Flow] since her abilities aren't very cheap. For your aura, I use [Corrosive Projection] because overall it is the best Aura, but if you prefer something like [Energy Siphon] you can use it.

For Focus School, I would recommend Zenurik or energizing dash. Her abilities are not cheap, and since we are utilizing Shield Gating, we want a good amount of energy so that we can cast her 4 to get our shields up again, and Energizing Dash allows us to stay near max energy with ease.

Enjoy Tenno!