Few things in Mass Effect are funnier than Bioware trying to play Kai Leng off as a badass when he's one of the weakest "bosses" in the series. There's also the in-game hilarity of Kai Leng thinking he's the pinnacle of humanity when he can't manage any part of a fight on his own.
Tela Vasir, bleeding and stumbling, was a tougher fight in ME2. She's able to hold her own despite the circumstances, potentially up against a biotic Shepard, Liara, and an asari justicar.
Boy, who are you kidding with that boastful bullshit?