Here is what Isekai no Seikishi Monogatari SS2 would need to resolve:
The final battle takes place in the upper atmosphere. Kenshi pilots the upgraded "Kuroki" (Black Seikijin), now upgraded with components from the Swan. isekai no seikishi monogatari ss2
Kenshi came to Geminar via a faulty dimensional ship (the Kamidake ). But in the last episode, his sister arrives, revealing that his father (Nobuyuki) and the goddesses back on Earth know exactly where he is. They were watching him the whole time as a "training exercise." Why? The running theory is that SS2 would involve Kenshi being recalled to fight a multiverse-level threat, forcing him to bring his Geminar harem to space. Here is what Isekai no Seikishi Monogatari SS2
The post-credits scene hinted at a larger multiverse threat, explicitly teasing a continuation. That was 16 years ago. But in the last episode, his sister arrives,