What happens after a rudder hardover?
With a fully deflected rudder the airplane will fly with substantial sideslip, and by dropping the windward wing it can be held on a straight course. This is usually done intentionally with gliders and light aircraft when they want to lose altitude quickly, because the high sideslip angle will increase drag substantially. If $\zeta$ is your rudder deflection angle, the slip will normally have a sideslip angle $\beta$ of between -$0.5\cdot\zeta$ and -$\zeta$, depending on the details of the aircraft.

If the hardover happens at high speed, the resulting aerodynamic forces will certainly overstress the fuselage and tail structure, and the aircraft will break apart and crash. No amount of pilot skill can prevent this!

If the aircraft survives the hardover incident, the best the pilot can hope for is a controlled crash: The sideslip angle will cause the landing gear to be torn off, and the dropped windward wing will provoke a ground loop - if the pilot tries to level the wings during the flare, the resulting yawing motion will ground loop the plane in the other direction.

I once had the chance to fly the prototype of the Swift S-1, an excellent Polish aerobatic glider. During one maneuver my left pedal got stuck, and I saw myself already sideslipping the plane into the ground. In the remaining minutes I tried to get the pedals unstuck and got lucky, ending the flight with an uneventful landing. Afterwards, I found out that the pedal mechanism had caught the wire from the battery, and my maneuvering had freed it up again. This was the closest I ever came to land with a rudder hardover, and I am not eager to ever try this out for real.