Ken is Twelve’s worst match-up. By far. I don’t see what makes Akuma a tougher match-up for Twelve. Air hurricane kick? If Akuma is going to spend that much time in the air, st. FP his ass. Demon flip? Same thing. LP SRK? Yup but Ken has the same thing, plus Ken can do a kara double SRK, plus Ken has better defence than Akuma, so it’s not even that big a risk for him.
It’s theory fighter, sure, but Akuma isn’t as much of a problem to Twelve as Ken. Neither of them are nice match-ups but Ken is much harder for Twelve to beat than Akuma.
Elena is also tough, granted, but nothing like Ken.