Regarding your Gatling Gigan edit: we typically don't count appearances in episodes' recaps, title cards/intros, or next-episode previews. The only exception I can recall is the Godzilla Singular Point credits, which feature a ton of characters/monsters who aren't in the show proper at all.
EDIT: Whoops, I got ahead of myself and didn't see that Les already said similar. Hopefully this adds a little extra context.
yeah I got it explained to me already. the reason I asked was because episode 0 counted for just an image but that was probably because it was the "pilot" so to speak
I forgot about that, but I think it could be argued the pictures in episode 0 are part of the episode. In subsequent episodes the format is: the narrative ends, it smash-cuts to the title card, then kaiju encyclopedia, the next-episode preview, and credits. In episode 0 the end of the last fight transitions directly into that narrated slideshow and then the title card appears, so it doesn't seem like a preview per se.
