A Broken Sword
Everything that Guts defined as a person was shattered in episode 370. The sword has always been at his side and during the Wounds chapters, Casca symbolically took the role of his sword.
In Sparks from the Swordtip, he ponders how he made important experiences and encounters as he was swinging his sword, that it feels natural to him. These momentary sparks gave him life even if its just for a moment.
Now with Episode 370 (and 364 by extension) it has become clear that he cannot create any sparks anymore with his sword having become too heavy to wield...
As Godo once said in volume 17, he has become a sword that has begun to break.
And also Flora mentioned something like this much later in volume 24: even though his sword was renewed in earlier chapters, it still will become heavy and blunt.
Statements that imo accurately depict his situation in newer chapters:
With episode 370 the trust in his sword and himself is shaken to the core once again:
HOWEVER there is some hope though. Sparks do not necessarily have to only come from two swords clashing, they also exist within one's consciousness...
as little lights that may guide you:
