2) Crocodile Beach
The second time Guts gives in to the armor is when facing the whale familiars.
Guts was extremely exhausted and ill due to the first time he’s used the armor, he is still weakened, barely being able to swing his sword, as noted by Puck and Ivalera prior this.
Later on that night him and his companions are attacked by crocodile familiars.
The crocodiles themselves are a gear up compared to the trolls. They still weren’t a match to Guts, but it appears that he was not only fighting the crocs, but also himself. Regardless, he still managed to keep his composure.
The situation however made a turn-around the moment the whale familiar came into the scene. He was now facing a new enemy much bigger than himself and at this point he didn’t know their weaknesses yet either.
What happens now is that Guts is fighting this giant monster all by himself and as he was distracted for a second by the Beast of Darkness trying to take over him – he was thrown onto a rock with one swing by the whale.
Not only he was hit by the familiar but also by the realization that he cannot defend himself or his companions anymore due to his weakened state.
Guts then decides to enter the Berserker Armor by his own will. During this battle, we see already established patterns too.
As he chops off the whale’s trunk, his astral wound on his chest flares up.
Again, his astral wound opened up, with blood gushing from his chest. The beast demands a blood sacrifice! Schierke also notes after the battle that his wounds need to be tend to.
After this, you see something very very interesting. We get a glimpse of what happens inside of Guts’ mind as he uses the armor.
What is this? See that pupil? He still appears to be to his senses. Earlier we established that these visible pupils indicate that Guts’ consciousness is still reachable. He also remembers how he slew the whale familiar – which will help him taking down eight more of them later in Vritannis.
He is contemplating how the roar of the sea is comparable to the roar inside of the armor. Fully conscious, he notes how he is being sucked into the booming roar of the armor’s od.
And this here is the beginning of the end. Guts has started to gradually lose himself here.
Remember that Serpico has incapacitated those crocodiles earlier. They pose no threat to them anymore. Still, Guts perceives them as enemies, feels surrounded by them and is thus exposed to great fear. He is fully conscious as this is happening. The reality the armor is presenting to him is thwarting his judgement. Schierke explicitly mentions this later in Vritannis too. I love how stuff like this is delivered both in visuals and later on dialog (to make it super obvious).
This page right here is when he loses himself completely:
You see how his pupils slowly fade away, as he gives in to the fear and rage dwelling inside of him, brought to the surface by the armor’s od. He is telling the beast to stay away again and again… his own words literally lose their strength and size, the more your eyes move to the left to read. Eventually, the voice of the armor drowns out his own voice and the beast swallowed him completely, as symbolized by his conscious eye vanishing.
Now we know that Guts has succumbed to the armor. In that exact moment, you see him walking towards his own companions. He will actively fight against this ALL BY HIMSELF later on during the Sea God Pirates fight!
…the moonlight boy intervened and stopped him. That was a damn close call!
The boy tells Guts not to be afraid. To me it seems like the boy knew what to say, as if he was about to calm him down. That means the boy can sense Guts’ mental state. He knows what the armor does to him – namely inducing fear and rage as we established earlier. But words alone probably wouldn’t have sufficed to get him back!
So the boy is touching the Berserker armor’s snout and white branches of energy spread around the helmet. You see how Guts regains his consciousness, as symbolized by his eye that you see again through the armor’s z-shaped eyeslots. The energy released as the boy does this is so strong that Guts is being catapulted back, away from his companions.
This is when Schierke reached out to Guts to finally draw him out.
Guts is using the armor by his own will and because of this, he kept some of his consciousness inside the armor. In the middle of the fight he started losing himself because the armor presented to him a reality that thrives on fear. When he finally lost himself, he was about to go after his companions but the moonlight boy interfered and brought back his (sub-?) consciousness. This allowed Schierke to finally pull him back to his human self.
Next, see what happens at Vritannis!