The trickiest part was actually clipping down, and hollowing out, the ankles of the Knight lower legs to have the Levithan feet fit into them. Again, a Dremel tool was used and by going slow it was no problem to make spot for the feet to sit in. My Dremel is quickly becoming one of my favorite tools to use and I can recommend one enough for extensive conversions like this. I will probably have to clip a few more odd sections of piping/brackets off the feet for them to have a better range of motion. The ball socket of the Leviathan feet still move, but they look good and definitely have a Chaos Raptor like appearance to them. This is good because I imagine a fallen knight as being more feral looking than what Forgeworld has done with it so far. Additionally, I'll go back through and take off some of the regular embellishments on the trim to Chaosify it a bit more with extended points and teeth like the Chosen from Dark Vengeance. This really only applies to the thigh, knee, and lower leg armor plates though.
*I'll edit the format once I'm home, I wish I could center the pictures on my iPad.*
The hip tubing, I used a piece of plastic trim to make up for the difference in diameter of the inner and outer tubing and make them fit snugly together.
I should be able to get time later today to get the torso built and dry fit with tubing to establish the height. The Leviathan feet already give it some additonal clearance, but ultimately I would like it be as close to a normal Knight in terms of size; as possible. Add a little more scenic of a base, and I think it won't be any problem at all to reach that goal.
Now what I'm left to ponder is the idea and story of this model for my army. I thought about having it be a relic left over from House Devine, using a Naga motif to show the house before the unification with the Imperium, but I have also thought about taking it a little further and going full Slaanesh Subjugator with it as well. It wouldn't be to hard to make claws from Tyranid scything talons and the back guns would be a fun thing to build as well. Or, since the Mortis comes with a claw hand, get the other claw hand and have a single back cannon, since I'm leaning toward a Paladin anyway. Or just do a Gallant with the back mounted autocannon and then visually all the bases are covered. I know I'm still getting started with the the chassis, but it's starting to be more complete in my mind and that makes the build go faster.
I'm excited to see where this will go in terms of a finished model, and it's all I can do to not blow off everything and work on it for the rest of the day and well into the night. But I want to help out with the the bronze pour at school and wrap up a few loose ends before the weekend to really get started on this later this evening.