How do I slay the khez in the 2 star quest.?

Umm... Do what you would do on every other wyvern
I had the iron katana at the time, your going to want something fast so you can get out of the way when it puts a short but effective electrical barrier around it's self, so when it's body starts to have blue electricty around it GET OUT OF THE WAY!!!
If your using long sword (aka the katana's) press triangle+circle at the same time ASAP so you don't get hit when it puts the barrier around him
If your using sword and shield, it depends, if your attack his head, dodge roll AWAY from the body, same thing if your by the tail area, if your towards the wings, BLOCK!!! And if your weapon isnt drawn and your close to it, RUN!
If your using lance I would say press X so you step back, with the gun lance I don't kno, with the hammer or flute hammer thing, I don't kno, if you're being a gunner, stay close but not to close to the monster that way you have good acuracy, while you are safe from harm
Now when you have to fight the RED khezu, I think it's in 4* missions, STAY AWAY FROM THE HEAD AREA it has a new move where it stretches it's head REALLY long and whips it around, ull see eventually

Just bring a good fire weapon and attack it from it's side RED khezu is that you need instead of a fire element weapon use a water or ice element weapon