To 'complicate' matters further, his train is running late. [=his train is running late, which makes the situation even more complicated or difficult]
This 'complicates' things. [=this makes the situation more difficult]
Changing jobs now would 'complicate' her life.
(..) Dialogue: Marked=..,Default,NTP,!Effect,You're the youngest Seeker\Nin a century. Dialogue: Marked=..,Default,NTP,!Effect,This complicates things a bit. Dialogue: Marked=..,Default,NTP,!Effect,Catch the key! Dialogue: Marked=..,Default,NTP,!Effect,Hurry up! (..)2001 Harry Potter and the Sorcerer's Stone