Now that Striker has been outed as a quite literal empty suit, the big question (beyond simply how to defeat it) is - why is it doing all this?
The short answer is that Striker believes that it's simply following Commander Kugel's grand plan having landed on Earth, albeit taking it to a rather more extreme extent by positioning itself quite literally as God. Such is the reasoning spouted by Striker that even Chamber disowns his fellow support unit as something approaching delusional, stating quite rightly that becoming a deity and stripping humans of all of their rights to independent thought and action is actually the opposite of what such a unit should be doing.
While Chamber and Ledo face off with Striker above the skies, and with Ledo in particular taking some rather extreme measures to try and get an upper hand over their rival, it's very clear that they aren't alone in their fight. Not only is Pinion continuing to do all he can to destroy the cult created by Striker using the technology he's retrieved, but Gargantia also has plenty of help to offer with Amy taking to the skies while the fleet's top secret weapon lays waste to the enemy with impressively flashy gusto. Although Ledo is willing to give up his own life for the safety of Gargantia and those who have grown dear to him, it seems that Chamber has an entirely different idea about how his future should pan out as the series draws to a close.
Overall, I don't want to be too harsh on Gargantia on the Verdurous Planet - as a series it had no shortage of ambition, and plenty of interesting ideas and concepts to discuss and flesh out as the series progressed; something which it did impressively well during its first half. As things became more narratively complicated however, I can't help but feel that the show lost sight of the things that made it special, and by this final episode we were more or less being treated to a dumb action moving that occasionally paused to throw out half-baked musings in the form of dialogue that simply weren't all that satisfying. Still, at least we were granted a firm resolution to proceedings without any wishy-washy back-tracking, and taken as a whole I enjoyed more of the series than I disliked, which ensures that this effort still sits towards the higher echelons of everything I've watched this spring, even if it could have been so much more.