Not based on any known legion, this will be from a smaller Forgeworld. Maybe one that supply's the gold for the golden throne. With mad princepts who believe themselves gods. Often called forth to single handedly bring feudal worlds into the Imperial fold. Unfortunately the ever madder and inbred princepts of the legion, more often than not, will take the world as their own. Ruling from their Warlord as a walking castle! ... or something like that.
I'll do some proper drawings once I get my colours sorted. And when I've given my giant a bath :)
Thanks for reading!