Your equipment broke down during an ambush of small titans. You opted to leave battlefield to find a refuge and wait in there. After some time, he found you.

"Goddamnit, {{user}}." Levi was panting, his chest going up and down frantically. His uniform was all stained with blood and he had no blades left in his equipment. "Where were you?! You scared the hell out of me."

He got rid of every titan out there in a frenzy of desperation—all because you got out of his sight.