For the part two of Mobile suit Gundam Arein, its actually doesn't related much to the Gundam Arein itself. The series was call "Mobile Suit Gundam Arein : The Awakening of the Earth". It will be a single episode and from this episode, the ending of the first series will be review here.
At the end of the Mobile Suit Gundam Arein, VF main base was being attack and damaged heavily. Eneuf take the entire VF and its new developed weapon of destruction called "Mirror" to take down WU. With the limited number in VF, it strike directly to the heart of WU in the center colony of The Ark and break down the entire WU defense system. Leon and WU forces retreat into Second colony of The Ark. RS take this opportunity while both WU and VF was exhausted in the war. RS try to attack and destroy the remaining of WU forces but VF knew it and try to protect the WU remaining forces as he know Leon is there. Due to the forces of RS was too huge, Eneuf lure the main forces of RS to Mirror which make the RS forces stay linear back to its RS space Headquarter. During this operation, Leon MS was damaged and save by Arein but both stuck at the Mirror's target as the RS keep on pursue them. In order to save his friend while make sure the RS main forces stay linear with it headquarter, Eneuf push Leon MS away just before the Mirror fire. The entire of RS main forces was destroy together with its space headquarter near Earth. At the end, all three forces which are the RS, WU and VF was suffered heavily in this war and finally call the end. These three nation then signed a new agreement to stay peaceful in the space near Earth. Leon survive as the representative of WU while Leana became the representative of VF with Eneuf's son call Rident. These three nation were declared as the Space Alliance (SA) as they are no longer able to go back Earth due to the radiation.
The story of this episode start when the refugee of the WU in Earth who was left behind by the RS starting to attack the space colony from SA near Earth. These people called themselves the Origin (of the WU or Earth). They have suffer a lot from the Earth radiation. With the scrap from the WU and RS left on Earth, they build themselves a very strong forces on Earth and begin to assault and capture the space colony near Earth. Leon piloting its prototype Gundam from his friend (Eneuf) which called the "Vanator" lead the old forces from VF to stop this madness. Vanator was a project develop in WU by Leon and Eneuf before Eneuf knew his real identity. With the technology from the VF, Vanator are quite similar to the Arein but performance was slightly lower.
Although the SA technologies was far more advance but they never thought the Origin forces was not small too. This series will be the beginning of the true battle in between nation from Earth and nation from Space Colony. The leader of the Origin was only review on the next Episode ( The Legacy Return) while this episode is focus more on the rising Origin and the main focus character will be Leon.