Rip off 75% of the tentacles using traps. Finishing the quick time event. Run up the bridge and finish the battle. It is a piece of piss.

First, did you make the potion that Triss asks you to make, using the ostmurk? If not, you should mix it and drink it before the fight. It will make you immune to the Kayran's poison.

If you have the Kayran trap, place it and then wait near it. When the Kayran lifts its tentacle, dodge out of the way, and the tentacle will get stuck in the trap and get cut off.

If you don't have the Kayran trap, use your Yrden sign to place a magical trap on the ground. Then do the same thing, waiting for the tentacle to raise up, then dodge to one side as it comes crashing down. It will get stuck in the Yrden trap. Then run up to the big, glowing red part of the tentacle and attack it. Geralt will cut off the tentacle.

Repeat this a few more times. If you used the trap, you'll have to use Yrden on the next few tentacles. Occasionally the Kayran will sweep its tentacle sideways, which can be a little hard to dodge. Sometimes it also gets mad and attacks with several tentacles at once, which you just need to dodge.

Eventually, after cutting off enough tentacles, you will trigger the QTE, where Geralt will ride on the Kayran's tentacle for a while. I recommend turning off "difficult QTEs" in the game menu, to make this section less annoying. After this, Geralt needs to climb the broken bridge to get at the Kayran's head. It will throw rocks at you. Use the Quen sign to avoid damage from the rocks, or you can try and take cover behind the rubble. When you get to the top, Geralt will automatically finish off the Kayran in a cutscene.

Don't forget to loot the Kayran's corpse, as it has several unique ingredients for crafting.

Thank you very much. I will try.

Forgot to mention you can use Quen in the earlier part of the fight too, to help prevent damage from the Kayran's tentacles.

If you still have trouble, you can give your savegame to someone on these forums and have them kill the Kayran for you. I've seen that done on these forums before. Unfortunately I don't have the game installed right now so I can't help, but someone else might.

I have one more question. Is this quest with killing Kayran necessary for proceeding further in game? Can 't it be just omitted?

It's required.

I used to suck on this fight but when I got the right stuff and got wised, it was piece of cake.

Although I almost uninstalled Witcher 2 because of this Kayran debacle.

By the way, if you can't still kill it off, sleep on it. Fight on another day.

Surely they can't be that bad at something so simple? I mean you dodge a couple of times, trap the tentacle, chop it off and repeat... I have seen my children play harder boss fights lol.

Keyran
My problem with with Kayran was resolved by changing screen display resolution to lowest level graphic details level to lowest then starting back from saved game

Last year when I played the Kayran battle for the first time I must have tried and died twenty times. Just couldn't get it. I picked up the Yrden trick via Sheila's suggestion but once I got good enough to get to the QTE, I always failed that. It was a miserable experience. I finally had to find a video tutorial on youtube smarter than me to help me out. I also discovered at that time the ability to turn "difficult QTEs off" as well as change the game's difficulty setting to low just for this encounter.

Annoying and odd mission as I never ran into anything else so annoyingly difficult in the game since even this year playing through it again.

Slightly late reply, but I failed this quest so many times that I hated the game. My "solution" was to temporarily switch the game difficulty to easy, which makes it so much more manageable. I hated doing it, but my philosophy is that if I'm not enjoying something that is supposed to be enjoyable I stop doing it or change the rules :D