Elden Ring: Messmer the Impaler (Shadow Keep) Boss Fight (SOTE)

Published: February 9, 2026 at 7:08:27 PM UTC

Messmer the Impaler is in the highest tier of bosses in Elden Ring, Demigods, and is the end boss of the Shadow Keep. He is a mandatory boss in the sense that he must be defeated in order to progress the main story of the Shadow of the Erdtree expansion.

As you probably know, bosses in Elden Ring are divided into three tiers. From lowest to highest: Field Bosses, Greater Enemy Bosses and finally Demigods and Legends.

Messmer the Impaler is in the highest tier, Demigods, and is the end boss of the Shadow Keep. He is a mandatory boss in the sense that he must be defeated in order to progress the main story of the Shadow of the Erdtree expansion.

So I finally made it to the end of the Shadow Keep after what seemed like an eternity of exploring the castle. It’s certainly not because I got horribly lost, it’s more a matter of... Okay, I got horribly lost.

But no matter, I finally found myself standing in front of the fog gate, the last thing between me and the boss’ horrible demise.

I had Hornsent available to summon in this fight and I chose to do so. As I have mentioned in some previous videos, I rarely summoned NPCs in the base game, but since I often felt like I missed part of their story by not including them, I have decided to summon them when they are available in the expansion.

Apparently, Swordhand of Knight Jolan can also be available to summon, but that requires progressing (but not completing) Count Ymir’s questline and I hadn’t done that at this point, so I only had Hornsent available. And of course, my usual sidekick, Black Knife Tiche.

Messmer the Impaler is a fast and agile boss with many fire-based attacks. Once he gets to around half health, he will transform into another form and be known as “Base Serpent Messmer” instead. In this form, he will sometimes summon a huge snake that really likes to bite people and swallow them whole, so watch out for that.

To be fair, this snake is far less annoying than another large snake I faced in the base game, but still, I don’t know what it is with these bosses playing with snakes just to scare me or something. I have a pet snake in real life, so if they really wanted to creep me out they should summon spiders instead or something.

If you’ve watched any of my recent videos, you may notice that I’ve switched weapons in this one. I’ve been using the Hand of Malenia katana as my mainhand since I defeated Malenia as the last boss in the base game, but it occurred to me that I rarely used its special weapon art because it was a lot less formidable than Malenia’s version of it. Therefore, I have decided to switch to Rivers of Blood instead and focus more on the innate bloodloss-induced quality of the katanas I’m dual-wielding anyway. That actually seems to work quite well, as I managed to take off a huge chunk of the boss’ health at least once with that approach.

I overall found this boss to be a fun and reasonably challenging fight. It did take me a few attempts, but I have faced far more difficult bosses in this game at this point. Your mileage may vary though, some bosses that I personally find very difficult are generally considered easy, so I suppose it depends on build and playstyle

And now for the usual boring details about my character. I play as a mostly Dexterity build. My melee weapons are the Rivers of Blood and the Uchigatana with Keen affinity. I was level 210 and Scadutree Blessing 13 when this video was recorded, which I think is reasonable for this boss. I’m always looking for the sweet spot where it’s not mind-numbing easy mode, but also not so difficult that I will be stuck on the same boss for hours ;-)

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Fan art inspired by this boss fight

Anime-style fan art showing the Tarnished in Black Knife armor facing Messmer the Impaler holding a flame in his hand inside the candlelit Shadow Keep. Click or tap the image for more information.

Anime-style fan art showing the Tarnished in Black Knife armor on the left, seen from behind, facing Messmer the Impaler holding a flame inside the candlelit Shadow Keep. Click or tap the image for more information.

Anime-style fan art showing the Tarnished on the left facing a much larger Messmer the Impaler holding a flame inside the candlelit Shadow Keep. Click or tap the image for more information.

Realistic fantasy fan art showing the Tarnished on the left facing a towering Messmer the Impaler holding a flame inside a candlelit stone hall. Click or tap the image for more information.

Isometric fantasy artwork showing the Tarnished below facing the towering Messmer the Impaler on a candlelit stone platform inside the Shadow Keep. Click or tap the image for more information.

Fan art inspired by this boss fight

Further Reading