Wonderful, there is progress everywhere!
First question: Do you use Magic Set Editor? I'd recommend it. It has very nice sizecropping for the text, and gives you all borders (even picks the right one automatically).
Also I'd recommend some changes with the creature types: Put the Shadoll type in front of all other types, it's the dominant type of this tribal, just looks better and makes more sense.
The El Shadoll-people are more of a problem. Usually you don't have two worded creature types, so you would end up creating the type "El", whi would be weird. But what about this:
Correct me if I'm wrong, but the "El Shadoll" are like the big commanding dudes, right? Do all "El Shadoll" have own NAMES? Because if so, all of them are Legendary, so instead of adding "El Shadoll" you can just make them Shadoll [what ever the pffrrz you want] and instead change texts that search for "El Shadoll" to searching for "Legendary Shadoll".
For example, "Shadoll Fusion" would be more like this:
As an additional cost to cast this spell, sacrifice two Shadoll creatures.
Search your hand and/or your library for a legendary Shadoll creature and put it onto the battlefield under your control.
Sooo... let's look at the DETAILS! (Please keep in mind, that those are only suggestions. Most of them competent, but still only suggestions; This is YOUR adaptation of this YGO archetype, so you are the one making the decisions.)
1) El Shadoll Midrash
Is extremely overprized. I would reduce it's cost to {7}, maybe {8}. Problem here is, that it is very easy to kill of, once you have a regular flyer with at least 2/2 (which are VERY common) or some mass damage (also very common). Other than that, you might want to make its text flow more... flowing? Screw that, but you could write "Players can't play more than one creature each turn."
2) Curse of the Shadow Prison
Is a little bit too cheap. I'd recommend changing it into {3}{b}{b}.
Also, I KNOW that you are primarely focusing on porting the effects from YGO, whith out cutting them to much, but you'll need a lot of tweaking to make this one work... If you keep it this way, you should increase its ability cost to something around {3}{b}. It's everything but difficult to get those counters on it. Also, you could call them Charge Counters, instead of just counters; Doesn't change much, it's just about the flavor, you know^^?
But what you could ALSO do, is shifting it into something more similar to this:
"Whenever a Shadoll creatur dies, creatures your opponents control gain -1/-0 until end of turn." This way you could use it effectively, without spending too much mana.
3) El Shaddoll Egrystal (I just realized that there is a second D in there :/)
First of all: Reach. No. It works in the flavor of some green cards, but most of the time, it is both useless and not very interesting. Just give it Flying.
Since its ability is basically free (especially since the overall Shaddoll set is black, giving it some sweet GY-Synergy) you should add "Use this ability only once per turn."
I actually like the idea, that you don't have to tap it and hope you keep it that way. Also, you might want to turn this one down to {7}, too
4) El Shaddoll Fusion
Not to much to mention here (tweaked text somewhere up there), but what exactly is the difference between the two cards? What does the "El" do?
5) El Shaddoll Nephilim
I REALLY like this one. Once again, the Reach-dilemma, and you might change its cost to {8}.
6) El Shaddoll Sheknigiri or whatever his name is... damn I'm hungry...
This one is broken as fuck. A reasonable cost would be {8}, maybe {9}, and you might consider the afforementioned limitation of "Use this ability only once per turn.".
7) Facing the Shadows
For two mana, this one is nutz. My suggestion: Make it {2}{b}{b} and hide the fetching within an additional "cost" (if you didn't realize it already, this is a thing with black: It's like "my spells are stronger than their manacost allows but I DO have to sacrifice something" but in the end, they even profitate from their "sacrifice". GOD I LOVE PLAYING BLACK).
8) Shaddoll Beast
Make it {4}{b}{b} to leave it more room to be played out of mono-black. Don't need all these instances of "once per turn"; It taps already for its first ability and once it dies, it basically counts as another object, so at this point it's irrelevant (some wibbly wobbly rule stuff).
9) Shaddoll Dragon
Why no Flying? Also {3}{b} would be reasonable. Other than that, same as with Shaddoll Beast.
10) Shaddoll Falcon
Its first ability needs no tap; You can't tap within your graveyard (yet...)
11) Shaddoll Hedgehog
"Once per turn", just as with Shaddoll Beast, unnecessary.
12) Shaddoll Hound
Optjawsbu, which stands shot for " 'Once per turn', just as with Shaddoll Beast, unnecessary." Maybe make it a {1}{b}{b}
13) Shaddoll Llizard
Optjawsbu, as well as making it a {2}{b}{b}
14) Shaddoll Source
Actually works kind of well...
15) Shaddoll Roots
You can just write it out as:
Put a 1/4 black Shaddoll Plant Wizard creature token onto the battlefield under your control.
It has "When this creature dies add {b} to your mana pool. [ETC]"
Seriously? Shaddoll Plant Wizard?!
Anyway, keep it rolling, good luck, and have a nice day.