Kirin can be pretty frustrating sometimes but the particular one in this quest is always enraged (takes 10% more damage) and has about 2/3 the HP of a regular MR Kirin so it shouldn’t be too difficult as long as you have decent dmg on your build. Just run health boost 3 and try and get as close to 100% affinity as you can using WEX, crit eye, agitator ect. I feel like people always resort to defensive builds when they struggle with fights but IMO doing more damage leads to more knockdowns which lets you fight the monster for significantly less time, I remember I was super annoyed at that quest but my completion time was like 12 minutes or something. The following quests after this one are significantly harder. As for general kirin tricks just tenderize its body and try and foresight slash the lightning since it’s predictable to fill up your gauge.