A Liir in close combat is the most dreadful foe imaginable, unless you have developed specific technology to spoof his psionic and physical senses.
You cannot hide. Your life force and thought patterns are about as subtle as foghorn with a laser show attached.
If you can be "seen" sonically, you can be easily attacked--not only by his weapons systems, but by a tornado of whatever stray objects he has managed to tear loose from his surroundings. Everything under the size of a bread box in your ship is likely to come hurtling at you at the speed of sound.
If he understands the mechanisms which operate YOUR weapons, the tiniest telekinetic twitch can cause them to misfire or explode. The same is true of the tiny flicker of pressure it takes to burst the blood vessels in your brain, which are as easy for him to read sonically as the trail map in a city park.
This, of course, is assuming that he's very calm and being subtle. If he's hurt and angry, he'll get crude and childish--pick you up and crush you to jelly in a telekinetic fist, or batter you into spam against the hull of your own vessel.