This is going to be hard to do in pixel art, but I will try to explain.
His pants are not finished at his highest head point, but actually continue to go up.
He made holes for his face and arms at its lower part.
The pants don't go too high, so it won't seem anormal, (they should be big enough to stay balanced from the perspective of real physics, they will be just a little over the head and there will be the belt, to make it seem more like pants.)
I changed the color to not be pure black.
The design on him which gives a armor look is temporary and only a test.
It is supposed to look like normal pants in the finished version, but with shading.
THANKS!