Xenreas comment made me think... I decided to check his idea and as it turns out, [Octavia Prime] has no problem with maintaining energy during the mission (well, unless some mob sucks it), efficiency at 45% is absolutely nothing of a problem with this configuration, especially since the [Octavia Prime] has 744 at its disposal. In case of energy troubles ... we have Squad Energy Restore, we have Zenurik Focus School... and we have syndicate weapons that can give us back some of that energy from a syndicate blast.
So, in a nutshell, the above build is the result of a comment from Xenreas and related tests and my thoughts. Thank you very much for your idea and I apologize to everyone who already used some formas. You can save one (Aura Forma) if you choose not to change the polarity on the aura.
With this build she's strong, her skills are long which make them efficient, even with 45% Efficiency, and her range is doubled, so she actually can cover an entire room full of enemies.
I just can't stay in one place, watching everything dying by itself. I like melee in this game, so why not take advantage when I have cloak and melee boost? So if in any case there is still someone alive I use [Mire] with augment which help me maintain an energy pool and is useful as a weapon to finish a tough enemy.
You prefer to be more... static? Replace Resonator with Rest & [Rage] and keep in mind to use Energy Emissive Primary Color responding for Day Form.
Suggested Focus School is Zenurik (if you got problem with energy) or Naramon for its Power Spoke.
Suggested Arcanes are Energize & Guardian/Resistance.