Griffith
With the streak of a tear, Like morning dew
Yeah, these things aren't out of the blue, like Aaz said, in volume 23, Guts was "possessed" by the Beast with absolutely no other supernatural influence such as evil spirits. It just happened, though in a highly stressful and emotional situation, (which is still a really cool scene, seeing him look so dark and cold on the outside while the raging Beast represented his emotions inside, but I digress...). Here he's literally just sleeping and it's happening.
Anyway, I do think one could say it's related to the armor in that it's what put him in this condition in the first place, as well as arguably strengthening the influence of Beast in general, perhaps even when the armor is off. As Skull Knight warned him, and as we saw by his brief blindless a couple of episodes back, the armor is having a greater permanent affect over him, and his struggle to control the Beast is obviously a major dynamic of his use of the armor. And I think that imagery of the Beast in chains like that comes from Guts' mantras while in the armor, about how he's the one holding the bridle, is the one in control, etc. But could that fire the armor provides still be smoldering even when he takes it off now?
In any case, in or out of the armor, the Beast is still the beast that lives inside Guts.
Anyway, I do think one could say it's related to the armor in that it's what put him in this condition in the first place, as well as arguably strengthening the influence of Beast in general, perhaps even when the armor is off. As Skull Knight warned him, and as we saw by his brief blindless a couple of episodes back, the armor is having a greater permanent affect over him, and his struggle to control the Beast is obviously a major dynamic of his use of the armor. And I think that imagery of the Beast in chains like that comes from Guts' mantras while in the armor, about how he's the one holding the bridle, is the one in control, etc. But could that fire the armor provides still be smoldering even when he takes it off now?
In any case, in or out of the armor, the Beast is still the beast that lives inside Guts.