After rewatching Luffy’s Gear 5 battles with Kaido and Rob Lucci, I noticed a shift in his behavior. When Luffy first entered Gear 5, he seemed much more silly and carefree. However, as the Kaido battle progressed, he became slightly more serious. In his fight against Rob Lucci, though still playful, Luffy appeared to have more control and focus in Gear 5.

This led me to a theory: Vegapunk mentioned that it’s rare for a Zoan-type user to fully transform into their beast form without losing control of their mind. I think the first time Luffy entered Gear 5, the Sun God Nika had more control over his body than Luffy did. By the time of the Rob Lucci fight, Luffy had learned to exert more control over the Sun God Nika’s power. As he continues using Gear 5, I believe he’ll become more serious as he gains mastery over the form, eventually being able to fully harness Nika’s abilities without losing himself to its sillier side.

There’s also the moment when Luffy “died” and the Sun God Nika seemingly took over. I think Nika is drawn to Luffy’s carefree nature, which allowed Luffy to retain some control even in this god-like form. Additionally, since Gear 5 is extremely taxing on his body, this may further limit the Sun God’s influence over Luffy’s mind.

As Luffy evolves with Gear 5, he’ll likely strike a balance between Nika’s playful spirit and his own serious determination.