Witcher 3's Geralt fighting a Rathian from Monster Hunter: World

[Update]: Monster Hunter: World - Iceborne has continued the cross-over tradition by now including Resident Evil 2's Clair Redfield, Leon S. Kennedy and Mr. X!

After a rather long wait, Monster Hunter: World's recent PC update has finally added The Witcher 3 collaboration event. As you might expect given the name and the image above, the event introduced Geralt as a playable character with his own unique quest, voice acting, armor, equipment, as well as a fancy new boss to fight against - the Leshen. 

While the quest is certainly fun, and the Geralt themed armor decently powerful for new characters, the real meat of this whole collaboration event has only just arrived. By defeating the newly unlocked and extremely challenging Ancient Leshen you can now craft Ciri's armor, cosmetic variants of both Geralt and Ciri's armors, as well as Ciri's "Zireael" dual blades.

In order to access this new quest you will need to be Hunter Rank 50 or above, meaning that this portion of the collaboration event is mostly for end-game characters. That said, if you've completed the main Monster Hunter: World storyline, it is entirely possible to boost your Hunter Rank to 50 and gear yourself up to tackle this quest before it goes away on May 30th. So even if you don't match the requirements right now, there's no need to despair as they're really not as extreme as they sound.

That said, the fight itself is genuinely challenging, and it took me over a dozen attempts to finally get my first kill. My advice would be to get as many health boosts as possible in order to avoid being one-shot by the roots, bring a whole wagon of Flash Pods in order to keep interrupting his most annoying attacks, and just mostly play it safe throughout the fight. With a random group it'll likely take you around 20 minutes to kill the Ancient Leshen, so it really is more about ensuring you don't mess up, rather than worrying about doing the most optimal DPS at all times.

You can learn a little bit more about this event, as well as Monster Hunter: World itself, over at Steam. Good luck with the Ancient Leshen!