Here's my take on dark souls for those looking for a replacement/complement to severance: (Skip to the end for my verdict)
Severance is an action game with small rpg elements; Dark souls is an action rpg with an action game combat system
Battle is slower paced but more detailed (gameplay elements). Epic boss fights (think meskalandug)
Hard as nails
World is bigger and mostly non-linear
Scenarios and atmosphere are great.
Scale is excelent (which also means you'll be running around a bit).
Soundtrack and effects are very good
Much more equipment and a weight carrying system with nice feedback.
8 primary stats for player characters
Player characters are class-based but can become anything really, so there are no unique characters.
Some npc interaction (sometimes complex)
Story seems rich but can only be glimpsed
Very good replayability
Some more stuff:
There are no direcctional attacks but instead a normal and heavy attack. The normal attack can be used differently according to situations, like performing a counter or a running attack. You can wield your weapon with one or two hands. Two-handed attacks are stronger and some heavy weapons are best used in this way.
Defence also favours shields. You can block with a shield and if it is good enough the attack will bounce. You can also parry with most shields (similar to tukaram's/zoe's defence) and perform a quick time event counter move.
The other quick time event move is a backstab, good for fast characters.
Defending and parrying take up stamina, depending on what you're defending.
There is an epic amount of equiment, most of it usefull and upgradable.
Your character reacts to the equipment's weight. A full suit of heavy armor will make you move slower, but you will be well protected and won't feel most hits. Higher stamina will raise the weight you can carry comfortably.
Weapons cause more damage based on scalling. A katana will scale better with dexterity, whereas a heavy club works better with strenght.
Progress-wise dark souls is a rpg. You have a semi-open world and you can kind off choose were to go, and I say kind off because you will probably die a lot or progress slower if you don't take the "natural" route. There are some clues on this route, but in the very beggining players will feel a bit in the dark. Dark souls uses resting places/Checkpoints which allow you to refill your health and potions but also respaw all the enemies in the game world, so if you're low on health and can't make it to that next checkpoint you can calmly go back to the previous one (provided you killed the opposition along the way) and replenish your health as well as spend your experience points to level up or repair/upgrade your gear (experience points are also your currency)
The game saves your progress constantly (including when you quit or after you miss that hard jump) so there will be no constant save-load strategies.
Using the right analogue for the camera is still not very comfortable (used to mouse) but there is a lock-on and it's manageable.
There still isnÂ´t a perfect balance between shield block and shield durability: in severance you can block fairly regularly but it forces you to discard shields quickly and you usually can't block big attacks (minotaurs, chaos knights). In dark souls, with the right character build and equipment you can block almost everything and your shield will still last you for 1/5 of the game with the easy possibility of a repair. Sometimes when you block a weapon that's as big as you from a guy thrice your size it can feel a bit silly, but you'll still be happy to be able to do it.
In severance the player character's evolution is fleshed out by raising POW DEF stamina bar and hit points. Also the weapons are not trully weapons but a combination of POW and DEF. The only "personality" they have was the shape (reach, colision) and special move.
In dark souls weapons are more unique: a hammer is swung slowly, a big one very slowly. Heavy weapons usually required more strenght to wield while agile ones required dexterity. Basically every "normal" weapon can become usefull if upgraded and the player will choose based on his playstyle and how he wants to build his player character, and dark souls can do this as oposed to severance because it has a "true" rpg-aspect to it.
It also has some nice touches like various types of damage and effects (strike, slash, bleeding, poison, the inability to parry heavy attacks, the possibility of constantly block with weapons even if it is less effecive etc.)
On the other hand there are also some perpetuated stereotypes like some heavy weapons being way heavier than they really are (like big swords) which makes the slow combat even slower.
Replacement = no / Complement = definitly
When you finish a game many times what keeps you coming back for more is gameplay and challenge. Dark souls offers more diversity in armament and because there are more weapon "types" (axes, really big axes...) it even offers a lot more movements, but the normal / heavy simple variation is still, in my opinion, no match for the reward you get from mastering the 4 directions control set, not to mention severance's faster pace of combat which keeps things more interesting.
Dark souls joins my other two giants of combat gameplay: Oni and Severance
One final note with a SPOILER warning. This game takes the trophy for best final boss even if I hand it over with a glint of hate in my eyes