Dark Souls Campaign Mechanics

I want some tips on development of a Dark Souls campaign using 5th edition mechanics.

What are some do's and dont's for DM-ing such a campaign, as compared to other ones?

>no Lautrec
meh

This is what I've come up with so far.

Dont

This is a bad idea, find a system that has armor function as damage reduction.
Then have death cause large amounts mental damage.

The first question you need to ask yourself is: do you want the mechanics of dark souls (high difficulty, respawns, tightly tuned combat mechanics, etc) or do you want the universe of dark souls (hollowing, first flame nonsense, etc etc).

The mechanics of the game aren't married to the lore, so it's important to look at what you want first and go from there.

Step one: throw 5e out
Step two: get Dungeon World and Cold Ruins of Lastlife (inb4 Virt-style autist rage over DW)
Step three: enjoy the closest thing you can get to a Dark Souls RPG that isn't in Japanese/not even out yet

I want to use 5th as I haven't DM'd before, and this is the system I am most familiar with. However, I'm comfortable with trying 3.5 too.
I want both. I want the atmosphere of Dark Souls, but the difficulty that comes with it. But I want mechanics that can be understood easily enough by new and experienced players.

Don't:
>use 5e
>use 3.5 either
>use 4e either

Do:
>think about what exactly "Dark Souls" means to you
>realize that the quick, player skill-based, iterative trial-and-error gameplay of Dark Souls translates very poorly to the tabletop
>read and learn about RPGs that are not WotC-era D&D

>think about what exactly "Dark Souls" means to you
To me it's an overcoming of challenges. You're nothing but a weak human from the beginning, but you continue to get stronger.
>realize that the quick, player skill-based, iterative trial-and-error gameplay of Dark Souls translates very poorly to the tabletop.
That doesn't really translate to table-top, no. But the atmosphere, the adventure, and getting stronger does. Isn't that enough?
>read and learn about RPGs that are not WotC-era D&D
Where should I begin reading? All I tend to learn about Table-top RPG's is from other people. I've only ever played Pathfinder/D&D. I play plenty of other board games though, like Betrayal on the House on the Hill.