Yes, the Mindbound with double bladed sword can be built into a Mindbound, look at the sprue it's the bit right next to the double bladed sword. It look like a Khopesh (an Egypt sword)
Building my list and I find Thrallmaster are too expensive for my liking, I had to remove the Luminate if I want a 10-man list.
Hopefully we had more cheaper leader option in future expansion.
Also I like how they model the Thrallmaster to look like a range fighter that would stay away from CQC, turn out he fights with his fists and he hit like a truck.