Hello! Before I made this I searched for tutorials to hopefully get some help but I didn't find a single one. So here is what I did to make this cloak. It way be a little cheap looking but it can be modified to however you want it to look :)

What You Will Need:

-3 yards of red fabric (nothing too light or too heavy) also the amount of yards depends on your height. i am 4'11 and i had some left over.

-Hot glue and a hot glue gun

-needle and thread or a sewing machine

-scissors

-black fabric paint (optional)

-5 or 6 (depending on the version of Vincent) buckles

-black vinyl or leather straps

-E6000 glue

-craft foam

-Xacto knife

-Plastidip

-silver spray paint

Step 1: Cut Your Fabric

With my height I used 3 yards of fabric. I folded it in half and cut it. One half will be your cape attachment. with the other half, i folded it and measured the length starting from my shoulders to my elbows. cut off where it reaches your elbows not cutting where the fold is, that will be the mini poncho looking attachment. the rest of the fabric will be your wide turtle neck collar, measure the width of your neck but make it loose. the fabric should also be tall enough to reach up to the top of your chin starting from the base of your neck when folded in half.

Step 2: Sew It All Together

start with the collar. Take the fabric you cut out earlier (the measurements from your neck to chin need to meet when folded) and fold it in half, you might need to insert a flexible cardboard inside the fold to make it stiff. Sew along the bottom to close it shut. Then bend it into a circle and sew where the fabric meets. this will be the back of the whole cloak
now we move on to the mini poncho looking thing. take the fabric you folded in half earlier and unfold it. Hot glue or sew each edge up half an inch so it creates a nice even crease. fold it in half and hot glue or sew the edges together but leave the folded line at the top untouched, that's the top of your "poncho".
since the top of your "poncho" is a lot longer than the width of your collar, the top of the "poncho" needs to be gathered. hand sew back and forth while slightly tugging the thread so the fabric bunches together. before you fasten off, adjust the top of the "poncho" so it will fit nicely to the bottom of the collar. after you fasten off sew the two together so the two ends of the "poncho" meet in the middle to form an upside down "V" in the front. you should now face a front opened "poncho" with a collar.
now you will add the cape. because you will distress and weather the cape you do not need to make any creases, leave as is. bunch the top of the cape (one of the shorter sides) just like you did with the "poncho" and sew it to the base of the collar inside of the "poncho". now you have the base of the cloak! yay!
this part s the best part, tatter the bottom of your cloak! (if your doing Advent Children or Dirge of Cerberus Vincent) take your handy scissors and wildly cut out triangles from the bottom. also wildly cut out a few holes. make sure not to cut too into the middle of the cape.

Step 3: Weather Your Cloak

Get out your black fabric paint and outline every edge and hole of your tattered triangles. also add some shading so it looks REALLY burned! It should look something like the picture i provided. You will only need one coat of paint.

Step 4: Buckles Galore

depending on which version you're doing of Vincent you will need five or six buckles. Mine should have six but oh well I can fix that. this is also where your strips of vinyl or leather straps, and craft foam will be needed so make them handy! first glue down your leather straps (if you're cutting out vinyl strips you need to sew the last 2 or 3 down) the first two straps are on the collar, the third one is on the top of the "poncho" and the last 2 or 3 aren't "buckled" so 2 or three strips are on the left opening (when its being worn they should be on you left side) and the 2 or 3 strips should be adjacent and on the right opening (this way it looks as if the "poncho" is open because the straps aren't buckled). once your straps are down get your E6000 glue and glue on the buckles. the first three in the center and the last 2 or 3 at the ends of the straps on the left side. DO NOT HOT GLUE THEM ON, THEY WILL FALL OFF!

Next is the little things on each end of the straps (the silver things) take your craft foam and cut out little half circles to fit the length of each strap. After you cut out two for each strap (so 10 or 12), take an xacto knife and cut the foam so there's a little cross foam in the middle. after that you're going to want to Plastidip the foam on both sides twice. this way the foam will get hard and rubbery. Ounce its dry spray paint them silver. Attach each little piece with hot glue and you're done! woooo! congratulations! i hope this helped you!!!