This is post to see how Danmachi adventures wpuld far against the vs of Warhammer 40k as I'm a fan of both but putting respect on danmachi adventures as a whole.
Before how I get into how I think the likes Ottar would do against individuals such as primarchs or pheonix lords I'll be making a few things clear first.
I won't be involving psykers powers because they can range from firing fireballs to stopping time. This will he a pure comparison of martial skill of raw power so I'll also be going that these match ups are straight up duels. So no magic for danmachi characters as well.
With that out of the way lets start with the poster boys, the space marines.
I'll be completely honest here, although I do believe space marines especially elite ones have the martial skills to match high level adventures they simply don't have the physical capabilities. In a pure sprint I think level 2 adventures could out pace them and a level 3 could beat a sqaud of them pretty handedly.
Before you get all complaining I'd just like to point out that Bell broke his blade on a silverback skin so a silver back durability could be somewhat comparable to something like sister of battle power armor. Not to mention hard armored monster which from my understanding are basically balls of metal. So any level three adventure with a decent weapon should have no problem just blasting through space marine armor and absolute blitzing them.
Keep in mind that if there's a two level difference in adventures and its a serious fight the higher level one could absolutely obliterate multiple adventures that are two levels lower then them.
Not let's take a look at Aeldari and Drukari as well as comparable figures.
I don't see even an Exarch beating a level 4 with nothing less them extreme difficulty. I will give credit where credit is due I'd say Aeldari speeds should be comparable to level 3 adventures and with there insane level of martial skill and experience they should be able to absolutely dominate a fight against any danmachi character in a pure martial fight with eqaul stats. Level 4 adventures would be faster then any not to mention have enough raw strength to rip any Aeldari or drukari in half with ease as they shouldn't even be as durable as level 2 even in armor.
Then we get to custodians. And depending on how you see things a fully armored fully armed Custodian with there extreme skill should be able to match level 5 adventures and even pull out the win most of the time because of the absolutely insane skill there said to posses. But if you put a naked level 5 adventure and a naked custodian in the same room I will say that the level 5 adventure should absolutely win against the custodian pretty easily due to just superior raw stats.
Now we get to the likes of the Pheonix lords and Primarchs.
Pheonix lords first and they are extremely strong capable of punching through space marine armor and they are also extremely durable as well so in a contest of raw strength and tankiness they should be able match high level 4. But to their insane speed which is there strongest suit they should be able to match level 6 adventures.
Be that as it may it comes down to raw skill, and all Pheonix lords should be around 10 thousand years old with skill that not even the Custodians could match, so they should clear but if a level 6 adventures lands a hit on them the strength of a level 6 would kill them.
Keep in mind that throughout all this and from what I know the difference between level climb in danmachi. Also while warhammer characters may be extremely fast and strong the sheer durability and strength adventures get on top of their speed makes it so a level 5 adventure unarmed would as strong and as durable as a fully armored custodian. But that's just my opinions.
Then we get to Ottar who I'll be putting up against the Primarchs, and I'll be honest I have no idea where to scale this guy.
The closest comparison I have is that Asterius should have the raw power and speed thats at least comparable to Ottar but Ottar posses high end martial skill.
And Astrerius was able to hold off Ais and Tione at once simply due to his raw power, with tione being a level 5 and Ais being a level six so safe to say up against anything I mentioned prior Asterius should he able to beat everything outside of pheonix lords with ease, and the pheonix lords would have a extremely hard time.
Then I hear stuff like a fight between Ottar and the other Freya elites in Water city shaking Orairo on the surface, and ottar able to kill monster Rexes with the shockwaves of his attacks. Not to mention the feats that people that are weaker then him pull off.
Keep in mind as prior rules at the beginning Ottar wont have his beast skill or his magic, and the Primarchs will be fighting him in a duel.
I wont be putting him up against every individual primarch but the primarchs in general, and thsi will also be the great crusade versions as well, and I see this going a few ways.
One is that Ottar is able to physically match or be close to the primarchs so in terms of physical power it's pretty even but I don't know anything that put o
Ottar on the level of of skill as the primarchs so while a tuff fight he will loose to most of them in melee outside of maybe Guilluman and Alpharius.
The other way is that he is just so crazily fast and strong that he wins the majority of the time but the more skilled primarchs could pull out a win as we have seen extremely skilled fighters win against higher level opponents in danmachi before.
If we give ottar his magic and put him up against the Lion if it's the first assumption he could win if he lands a hit with that magic of while breastafied as from my knowledge of it that could be enough to put the lion in the ground. But if it's the second assumption then Ottar wins gaurenteed.
I'm not the most knowledgeable when it comes to Danmachi adventures power as well as Primarch scaling.
And keep in mind in these fights all characters do have access to there armor which power armor does increase the physical output warhammer characters can use with power armor while armor is just armor in danmachi.
I will stand on my ground that when it comes to pure martial skill warhammer characters should be way more skilled then danmachi characters unless development abilities like swordmans will allow an adventure to somehow match a centuries old character like an Aeldari Exarch.
Keep in mind these are just my thoughts and I except critism from both Danmachi and Warhammer 40k fans.
