Thanks for answering! But now I'm curious, my friend sent me this when I asked him about them. Do you agree with it?

So, did Dave Johnson come up with the super-hot plasma energy, rocks and magma aspect of Heatblast's appearence? Because in even earlier unused character designs that were created by Steven E. Gordon, Inferno already had this aspect. Also, Joe Casey said he came up/gave the idea/created Heatblast.

Joe Casey stated he created Heatblast, but did he come up with the magma-rocks and super-hot plasma energy aspect? In Steven E. Gordon's designs, Inferno already had this aspect, but in Dave Johnson's early concepts he had a suit like NRG, he said that he was never shown the earlier designs.

Thank you a lot for sharing it, it'll help so much. By the way, would you happen to have those for the episodes you worked on the Season 1, 2 and 4? If so, can you upload it too?