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In the later part of Second Bloody Valentine War ZAFT was experimenting with many new machines, some of them were classified TOP SECRET and all documentation of them was destroyed.
One of those projects was XMF-43S Volition, while externally reassembels ZGMF-42S Destiny, this unit is much closer to GSX-401FW Stargazer. Sharing three of it main features - AI Control Unit, "Voiture Lumiere" light propulsion system and nanomachine repair system along with added weaponary of ZGMF-42S and new prototype N2 Powerplant Unit this unit was the biggest failure of Asimov Design Bureau.
Entire core is built around N2 Powerplant - dual nuclar drives that can work in perfect synchronisation to achive unbelivable amount of energy produced, main drawback is radiation wich leads to propably main "flaw" of Volition - AI Control Unit. Based on data aquired from Stargazer ZAFT developed their own AI wich uses powerfull quantum compueters, aditionaly they inplemented battle data from many units piloted by Ace Pilots, such as Athrun Zala, Shin Asuka, Rau le Cruest, Rey Za Burrel, Heine Westenfluss, Gai Murakamo and many others even battle data from orignal Strike - tactics that were used by those pilots were a "base" for AI to learn from. It self learning capabilities allowed AI to eveolve over time.
Name "Volition" was chosen as a cruel joke for AI that must listien to it's human masters. Amount of raw power allowed ZAFT engineers to create, along convencional drive unit. a "Voiture Lumiere" based propulsion system far more powerfull than ony other known unit - this power manifest itself in form of power fluctuations in the Wings of Light, that makes them look like a living organism, as one of rookie enginiers said: "This looks like an angel!", altough none of the high ranged oficcers would say so in a official announcment, it was known that even chief enginiers seconded that opinion.
One could ask why such powerfull unit was a failure, the reason is quite simple, AI after analazing all availble data of Ace pilots decided that one with enough power can change the course of history, comparing data about units used in both wars and other smaller conflicts had brough it to conclusion that all of them were inferior and still managed to acomplish something. AI made a chice and rebelled against its creators in order to achive true freedom. and so name "Volition" wan't just an empty word anymore.
As expected ZAFT oficials couldn't allow such loss, wich is why special pursue unit was created. After first battle it was alredy clear that there is no way to re-capture Volition. The more AI was fighting, the more skilled and powerfull it became, that was the reason for use of gamma type laser against it. Haveli damaged Volition fleeed thowards Mars moon Phobos were it was lying dormant with nanomachines repairing till CE 82 - the begining of Martian Rebelion. Wrecking havoc in Mars sphere for next 3 years Volition became main obstacle to end this war. After XMF-43S seeked a place in wich it could allow nanomachines to fully reapir and self-upgrade. That's why Admiral Zala dispatched along with Avalon Strike Force in CE 85 thowards Asteroid belt - to seek and destroy source of so many tragedies. Avalon's 4 Re-IG units weren't enough to destroy Volition but they managed to chase it of thowards edge of Solar System. It is uknown what happend to XMF-43S Volition after that.
Pictures show Volition just before its flight towards Asteroid Belt