Zarkith continued to lean into his strike even has his opponent reacted in the oddest fashion he had ever seen. The dark haired human dropped low then released his sword. Zarkith had just enough time to register that move just moments before his sword clashed with the now seemingly immobile katana. The great sword rose up, hit the midsection of the weapon...and sent it flying away with only the oddest and slightest hints of resistance. Unknown at that moment to Zarkith, Mordem had immobilized his magic sword, however, unknown to Mordem, Zarkith sword's own magic activated upon contact, dismissing the enchantment that allowed the katana to defy physics. Thus without that makeshift barrier nothing was preventing Zarkith's great sword from sailing upward and severing Mordem's left foot at the ankle, a slight turn of the blade was all that was needed to adjust to Mordem's new position with him facing Zarkith now. As Mordem had no idea about Zarkith's swords magic, this turn of events was likely to completely catch him off guard, cutting his word short. 

Assuming the cut landed and left the dark haired man hopping on one good leg, Zarkith would have continued into his ox guard, leaving him in the prefect position to stab forward or defend against another aggressor. Zarkith had fought in enough battles to know that it was often truer than not that the warrior you didn't see was the one that often killed you, and not the one you faced off against. His opponent was also unlikely to reach him with his strike first, as Zarkith had superior reach and was already in mid swing.