Draconious failing

Can anyone tell me why my draconious uses wild fire in ladder instead of fire blast? Is it just the derpy AI and if so can I fix it?

[Koenaj]

Are you sure your Draco didn't use all its Fire Blast+2 PP?
Otherwise, there shouldn't be a reason for your Draco to use an actual attack, let alone its weakest Physical move.

Following current AI movements, Draconius should use Celestial Prayer.

I'm not sure it's correct or not, but i think the result is already decide once you choose the opponent. If the system decides you have to lose, your monsters can do anything that make you lose. Even though your Draco use Fire Blast it maybe missed so that you lose. If it's decide you win, even though you use Wild fire it can be critical every time

[Koenaj]

I'm not sure it's correct or not, but i think the result is already decide once you choose the opponent. If the system decides you have to lose, your monsters can do anything that make you lose. Even though your Draco use Fire Blast it maybe missed so that you lose. If it's decide you win, even though you use Wild fire it can be critical every time

Hit the nail on the head, forgot that factor.
This would indeed be the case for your Draconius to use Wild Fire instead of Fire Blast!