The fight with the Sea God has been compared to Griffith meeting “God”. The Sea God has a heart that has eyes all over it, and of course is heart shaped, so is God. In comparing the two, Griffith gave into and realized his dream by telling God his ambitions. Guts did just the opposite. Griffith sacrificed everyone he loved, Guts protected everyone he loves. So you comparing this to Ganishka is not that far off either! I’d definitely say it’s very similar. With each arc, back story and surrounding characters, you get lots of mirroring and as Flora says, paraphrasing here, time is like a spiral, it will repeat it self but not exactly. That is the structure of this whole story.