A few things you should bare in mind when you first find the quest that the old lady represents to you:

1- You MUST do the quest or else the quest will b gone if u do another quest. So get equipment ready.

2- It might look pretty but it WILL try and kill you and will probably do that on your first attempt (you have 3 lives) it is aggressive.

3- When u try and hit it most of your attacks will not work (sparks will flare) u will hit it succesfully only when you hit it head on at its head/chest, since its quite a small unicorn. Note: the sparks count as a hit and does do SUM damage but not a lot.

4- It glows brightly at the start but you will now when its weak because its mane will not glow and it will try and run.

5- Try using a type of fire wep and good anti-elecric armour because it hits hard. Preferably a g-sword as it can block the kirin's charges. I first beat it with a ravager blade+ and full blango armour.

Hope this helps.