Madness

Leo saw the Black Sun enlarging in the sky with genuine fear in his eyes.

He was not a gaming nerd and hence he had no idea about the sheer catastrophic power of the Black Sun, as per the game's historic lore.

However, he recognised the move from the list of the game's strongest moves that Captain Kid had given him, and hence he knew that it was a (Divine) ranked move at the least.

*Shiver*

Watching the Black Dragon enlarge it into a larger and larger mass with every passing second sent a shiver down his spine, as Leo understood at that moment deep down in his spine, that he could not hope to block or stop that move.

[Full Counter] was not going to work on a move of that size and power, nor did he have the strength to physically return it even if he tried.