The Castellans of the Rift tend to follow the Codex Astartes when it comes to chapter organization and heraldry, though with slightly different colors for veteran sergeants and lieutenants which incorporates the stripe on their helmet.
Credit: Games Workshop
Painting the Chapter Icon
Zuul the Cat: I tried hand painting this symbol and using transfers to get this symbol done but nothing I did looked good. What I recommend doing is either finding someone that makes the chapter symbol or you can hand paint a red X and place a skull on the intersection part, then chip the entire area using
Ogryn Camo and a sponge. Unless you're really good, then you can hand paint this symbol, but it's beyond my ability!
TheChirurgeon: This is a really tough one, but I'll tackle it. You can build the symbol using two other transfers - the red chains from the Black Templars transfer sheet, and a skull from the same sheet - and if you don't want to freehand anything that's probably your best bet. Otherwise, you're going to have to freehand some or all of it. Here's my process for doing that.
Start by painting the basic lines for the chains across the shoulder pad. I eyeballed this and it ended up off-center, which was a mistake. I'd recommend starting by putting a small mark in the center where you want the chains to cross, so you can use that as your guide to make sure you paint through it when you paint your chains. The good news is that if you do end up off-center, your skull will just cover that up anyways.
Once you've painted the lines, go back and paint the links. This is just adding a set of boxes to your line. Finish these by adding a small line of Ogryn camo inside each box, and boom - relatively easy chain links. At this point I'd recommend putting a skull transfer on over this instead of freehanding the skull, but if you really want to do this, I did a quick skull on the pad as well.
This is a pretty quick skull but you get the idea from this what the process is. I start by painting the center line for the skull in Wraithbone, then draw the outline around that, and fill that in. Use Ogryn Camo to make the teeth marks and Abaddon Black to do the eye sockets and nose.