Mists of deception make my 8 Marble Oracle dead?

[Cipher]

Hi all. I am playing a MP game. Last turn there was a big fight when I (ma agartha) try to storm Pythium's capital. After a huge fight, my force manage to make Pythium's force route, at that time I still have a big army including 8 Marble Oracle (fully armored) many mages and agartha statues. see the screenshot here


Then incredible things happened, this big army just disappeared step by step. I watched the battle slowly, noticed that in one turn, suddenly 3 MO disappear. All MO has more than 100HP, It's not likely the Phantasmal Warrior can kill it by 1 hit. I have no idea about this. Is this because Mists of Deception has the function that enemy could lost himself in the mist? or a big bug?

The starting force before battle can be found here