The first 3 magma pics didn't show up for me , but i think it's how Oda drew flames/fire more recently .
Here was how he drew a flame for ch. 1051's cover ( which is a result of Ichiji's attack ? ) .
https://mangasee123.com/read-online/One-Piece-chapter-1051-page-1.html .
Either way , i think King's and Kaido's Flame Dragons are hotter and more dense than the usual flame/fire still .
but Magma is still denser and heavier than even King's/Kaido's Flame Dragons .
Magma is melted rocks anyway .
It'll be cool for Akainu if he can transform to a giant ( like GreenBull ) and achieve a durable form with all the available rocks in his Magma .