I Like to stay up close with lían. Once you dive her use DS into melee she will then panic últ if she has it and you can counter with obliterate or ult. After she is a free kill.
You counter raum with your high sustain and cripple.
Tips:
Keep medium range
If Raum últs:
use obliterate or ult to counter
If he runs you can cripple him w/5stackDS