Look like no dropping from this fight
I dont think the dude has any intention of fighting, rather, winning.
He seemed to be very ok with his son dying, his heir was burned and crippled, his favorite servant died killing his psycho son.
Like many old men, they are leaving a world that is significantly worse off than the one that recieved them, I think he wants Ushio to wreck him so that he can go out in a blaze of glory.