[Webcomic] MSPA: Let me tell you about Homestuck...

I noticed that too. I assumed...

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He either did it on purpose to bring Terezi's guard down or it's a fluctuating thing. I doubt it's the latter because I was sure that he actually needed sopor slime to be his "old" self.

Option C

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Read this theory on the forum, that when Aranea mind controlled Gamzee again, it had reset his behavior back to what it was before, aka murder mode.

Adding my own twist here: But, since Gamzee was obviously badly hurt, he had a brief moment of clarity before he totally went back.

Option D

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It may be his Rage powers. My theory here is that it automatically kicks in when grievously injured, possibly as a self-defense mechanism. Kind of like video game mechanics for a boss, where at their lowest life they become their most dangerous. The reason Gamzee had a moment to be his old self was because his Rage powers needed a moment to realize "HOLY SHI'T GAMZEE TOOK A LOT OF DAMAGE". Why it didn't kick in for Caliborn? Probably because Gamzee's Rage powers actually only kick in when he takes a certain amount of damage in one instance/hit. When Gamzee was released from mind control, his body realized all of the damage at once. What I imagine Rage powers to be like is that at highest mastery, Rage powers can activate with less damage, or even at will.

tl;dr Gamzee's Rage powers activated because he took X damage in Y time.

./conspiracy theory