Success

You wait for one of Klarg's downswings before lunging straight into the middle of his frenzy of attacks. Right as his chest. You thrust into his center line and jam his movements, forcing Klarg to either put a pause in the frenzy of attacks, or be forced to make off-balance attacks should he choose to continue. Regardless of which he chooses, it did not matter as he hesitated in choosing, giving you the clear to slam your mace right into his chest.