Thinking about Necalli...
His normal form looks like your typical caveman idiot. When he uses the V-Trigger, his facial expression changes. Compare:
In the first image, he looks like he has a thicker brow region, suggesting a neanderthalic motif. His opening line is "Devour-our-our", and he says it as though speaking is not something he is particularly skilled at. While fighting, Necalli is hunched over, and his attack motions are brutish and imprecise. His attacks are typically accompanied by grunts or groans.
When he uses the V-Trigger, his face becomes more finely featured. His attacks are still just as impactful, but now they feel more like martial art techniques rather than the strikes of a brute. This is especially apparent in the Critical Art change. Normal Necalli's Critical Art is a Berserker Barrage X adaptation, and he flings wildly at the opponent while clawing them up. V-Trigger Necalli drags his opponent to the wall and unleashes one precise powerful punch, suggesting skill and sophistication.
My immediate reaction to this is that Capcom is defying a stereotype while also giving in to it. When people saw Necalli's preview, I heard two things:
1) "Ugh, probably some stupid beast man trope."
2) "Ugh, probably some noble savage trope."
Surprise! We got both in one character. He swaps between the two modes of being. What this means in terms of his character are uncertain, but the summary on his character says the V-Trigger "completely changes his personality". There is also something unmistakably supernatural about Necalli, what with the glowing anti-gravity hair he possesses in V-Trigger.
That's all I got.