Leiluo was already worried about Sylvanas. He had no time to deal with the Scourge, yet they stubbornly kept pursuing him, which infuriated him.
What angered Leiluo most were the three Death Knights. Their tactics were a real headache: they relied on their superior mobility to harass him relentlessly, keeping him constantly on the defensive. Then, when the army arrived, they would charge in all at once, hoping to bury him beneath a mountain of bones.
The three Death Knights were Falric, Maiev, and Saurfang, once Arthas's most capable subordinates.
Even after becoming Death Knights, the three remained Arthas's most capable subordinates. Unlike the mindless cannon fodder, they retained their full faculties. But they had no choice but to submit to Frostmourne and serve Bovar, the one who had killed their prince, Arthas.
Besides those three Death Knights, the other thing giving Leiluo a headache was Sindragosa, the Frost Wyrm soaring through the sky. Her ability to fly made it easy for her to find and harass him. Even after Leiluo had finally managed to shake off Falric and the others several times, she would catch up with him again.
Her great strength and immense power over ice made Sindragosa a mobile artillery platform. Leiluo was constantly worried that a blast of icy breath might suddenly come crashing down from above.
With someone he cared about on his mind and his pursuers refusing to let up, he was caught in a strange predicament. He could fight, but there were simply too many of them.
Leiluo was more than capable of easily defeating any one of the people pursuing him. But the moment he stopped, the seemingly endless Undead army would surround him like an ocean. In his haste to find someone, he had no intention of letting that happen. But