Pretty swell stuff!

Yes!
After a knuckle biting hair pulling process; I have finally found a primary source of the Mongolian invasion of China!
I have found a primary source written by Friar John of Plano Carpini !

Genghis Khan divided his Tartars by captains of ten, captains of a hundred, and captains of a thousand, and over ten millenaries, or captains of a thousand, he placed one colonel, and over one whole army he authorized two or three chiefs, but so that all should be under one of the said chiefs. When they join battle against any other nation, unless they do all consent to retreat, every man who deserts is put to death. And if one or two, or more, of ten proceed manfully to the battle, but the residue of those ten draw back and follow not the company, they are in like manner slain. Also, if one among ten or more be taken, their fel–t lows, if they fail to rescue them, are punished with death.

There is more to this source -

Moreover they are required to have these weapons: two long bows or one good one at least, three quivers full of arrows, and one axe, and ropes to draw engines of war. But the richer have single-edged swords, with sharp points, and somewhat crooked. They have also armed horses, with their shoulders and breasts protected; they have helmets and coats of mail. Some of them have jackets for their horses, made of leather artificially doubled or trebled, shaped upon their bodies. The upper part of their helmet is of iron or steel, but that part which circles about the neck and the throat is of leather. Some of them have all their armour of iron made in the following manner: They beat out many thin plates a finger broad, and a hand long, and making in every one of them eight little holes, they lace through three strong and straight leather thongs. So they join the plates one to another, as it were, ascending by de–grees. Then they tie the plates to the thongs, with other small and slender thongs, drawn through the holes, and in the upper part, on each side, they fasten one small doubled thong, that the plates may firmly be knit together. These they make, as well for their horses as for the armour of their men; and they scour them so bright that a man may hold his face in them. Some of them upon the neck of their lance have a hook, with which they attempt to pull men out of their saddles. The heads of their arrows are exceedingly sharp, cutting both ways like a two-edged sword, and they always carry a file in their quivers to sharpen their arrowheads.

this source is excellent as it gives a PRIMARY perspective describing the war!

more to come...including a snippet of my essay