"Ready as I'll ever be." Does this mean ready or not? Is this "I'm completely ready" or "I'm not ready but I have to"?
Master Yao: No! Po! The secrets are too powerful! You're not ready!
Po: Ready as I'll ever be.
It means that the speaker doesn't know if they are ready, but is asserting that they cannot imagine themselves ever being any more ready. It's like "I don't know if I'm ready for this, but I'll never be more ready so I might as well try."
Suppose I A say that
""I am ready as I will ever be""
It means A is so well prepared that there would not be any other time when he would be even better prepared.