Retaliation What If
This is just about what happens in a What If scenario if James Ironwood succeeded on destroying Mantle, then he faces the price for that.
Disclaimers: I own nothing
In a what if scenario, the Galactic Republic did everything they could to evac all of the people Mantle but unsuccessful due to an interruption caused by the CIS and they never got to Mantle in time. So with that, the now insane James Ironwood drops the bomb destroying Mantle and all of the people in it much to the everyone shock of the monster that James Ironwood has become which is exactly what the CIS wants him to be. But the Galactic Republic vows retaliation and they won't let this go unanswered, plus a promise that James Ironwood and those who follow him will be punished most severely.
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Eventually what James and Atlas has done just to get Penny to return brought the whole wraith of the Galactic Republic but not before the CIS shuts everything down in Atlas leaving it completely helpless and defenseless against Republic Forces and their Allies, that also includes a revolt by the Atlas people who are angry at James Ironwood for the monster that he has become. Yeah the Republic had their BTL-A4 Y-Wings bomb Atlas destroying with some help of the Imperial-Class Destroyers and Victory-Class Star Destroyers hovering high above Atlas. AT-AT Walkers, HAVW A6 Juggernaut Tanks and various Republic land vehicles join the battle and overwhelmed the defenseless Atlas.
Eventually Clone Commandos and Clone Troopers cornered James Ironwood and his loyal Ace-Ops followers and told them that they will face trial for their crimes which is war crimes before stunning them.
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In trial, James Ironwood keeps repeatedly saying that he sacrificed everything for Remnant, for Atlas and says that he was only doing what's best for Remnant and no one is grateful. Clone Shock Troopers with Electrostaffs batters him with it repeatedly as Republic Supreme Leader Hakaze Kusaribe reminded him that he was just the CIS's puppet and they are responsible for putting him as General and Headmaster of Atlas because they knew about his fear and paranoia so they use him and Atlas to do some damage and weaken all faction against Salem and then the CIS.
So with that James Ironwood and his followers are found guilty for their crimes and are sentences to death by death squad. Anything that James Ironwood says just to justified his actions are ignored before he gets a his cybernetic armed ripped out by a Clone Blaze Trooper.
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James Ironwood and his followers are all shot dead by 501st Legion Clone Troopers armed with DC-15A Blaster Rifles and then destroys their dead bodies with grenades. Lasty Atlas is destroyed by a single shot fired by the CIS's Lucrehulk-Class Battleship now Atlas's usefulness is finished.
After this the Galactic Republic will continue to defend Remnant from Salem and her forces evem from the CIS too.
End
Something else in Villains Wikia that made James Ironwood just as insane due to his fear and paranoia, in the Trivia when James lost his arm and replace it with a Cybernetic Arm, well that ended making lose his Humanity as well but that could have predicted his downfall into becoming a Villain.