Intent to Kill, Sword Intent Awakening

"Eternal Freezing Domain," Klaus muttered.

As soon as the words left his mouth, the tribulation ground turned ice-cold, and the surface began to freeze. The monsters charging on the ground were instantly encased in ice. 

It didn't stop there; those flying were slowed by the biting chill and thick humidity of the ice.

"Much better," Klaus said, focusing intently as he began slaughtering the monsters with his sword.

During his campaign for revenge against the Dark Order across the cities in the Northern Union, Klaus killed three sovereigns and several Sages and Great Sages. 

It was then he first felt the stirrings of his sword intent. At first, he thought it was an upgrade to his slaughter aura, but he was mistaken.

According to the Senior, his slaughter aura was somehow linked to his sword intent. This connection, combined with the fact that his sword was bound to his soul, accelerated the awakening process.