"You take heroes much too lightly"
He did it once with the witch, I hope he won't make the same mistake again.
He definitely won't take this one lightly for sure, as he knows the strength difference is overwhelming.
This is probably a trap where Idly will be supposed to kill her father when she gets "rescued" and the fight here is just a stage to make Mr Hero focus on the "kidnapper" rather than the "hostage". From the previous chapters, the MC doesn't have a thought of overcoming the strength gap by himself.