>>56273202I feel like this is one of those background lore things that GF keep to themselves that'd only be confirmed in some obscure guidebook or something, like how the 1997 Pokedex book in Japan revealed that Pokemon shrink into Poke Balls or that the reason only Nidoran F can breed is because Nidorina and Nidoqueen are canonical sterile.
Maybe Gigas is dormant for ages and due to its sheer age it can't move about as well as it once could or something and because GF are autistic about their lore they refuse to allow it to function in any way other than with Slow Start.
