Whether it's a Goodbye Scene or Fall or Defeat or Death ... etc
Old Legends always receive those Scenes not long after their Signature Attack Reveal.
Oda did it First with Neptune in Fish-Men Island Arc,
He did it again with Chinjao & then again with Streuseun & also Hyogoro,
Oden & Roger received Same Treatment in their Flashback,
Big Mom too & most recently Garp (Even WB still Showcased his Signature Attack before Dying, even though He didn't Name it)
It's clear how Oda handles these Relics,
So since Gaban showed his Signature Attack recently against Luffy/Zoro,
That means He is Going Down very soon, and it seems it's happening in Coming Two/Three Chapters,
I wonder how it will Play out,
I also wonder if Jarul too gonna showcase his Signature Attack (As He is this Arc's Version of Neptune, Streusen, Chinjao & Hyogoro).