Correct me if I’m wrong, but since Ganishka’s huge lightning mist form is an astral body created using some mix of water and wind magic, does it mean that he never really had an actual “true” apostle form?
Ok. I remember that which was also why I was really confused about what Schierke was saying about him. Thx for the clear up.The incorporeal fog form is his apostle form. We can know this with certainty because of the flashback in Ep 303, where we see him in fog form immediately after his sacrifice. But you're right that the fog itself is something he manipulates around his astral body, as Schierke explains. Still, that doesn't mean that magic was involved in his apostle form. At least, not any more than a standard apostle's form involves evil power.
Ok. I remember that which was also why I was really confused about what Schierke was saying about him. Thx for the clear up.
What Schierke is talking about specifically in the scene you're referring to is his giant "cloud mass" form, which is something achieved through a combination of magic (astral projection) and his apostle power. That's why she says so. That's also why, after Guts strikes his weak point, that cloud form dissipates and we see him far away in his quarters screaming in pain.
Ganishka was pretty unique, both because of his unusual apostle form and because he did use it alongside some rudimentary magic thanks to Daiba's knowledge and skills. That's how they could create and control the Daka and Pishacha.