Not exactly merrish, but they are opposed to Lorkhan and creation, unlike other Mannish races.
From the Yokudan monomyth, http://www.imperial-library.info/content/monomyth-yokudan-satakal-worldskin:
"Ruptga was able to sire many children through the cycles and so he became known as the Tall Papa. He continued to place stars to map out the void for others, but after so many cycles there were almost too many spirits to help out. He made himself a helper from the detritus of past skins and this was Sep, or Second Serpent. Sep had much of the Hungry Stomach still left in him, multiple hungers from multiple skins. He was so hungry he could not think straight. Sometimes he would just eat the spirits he was supposed to help, but Tall Papa would always reach in and take them back out. Finally, tired of helping Tall Papa, Sep went and gathered the rest of the old skins and balled them up, tricking spirits to help him, promising them this was how you reached the new world, by making one out of the old. These spirits loved this way of living, as it was easier. No more jumping from place to place. Many spirits joined in, believing this was good thinking. Tall Papa just shook his head.
"Pretty soon the spirits on the skin-ball started to die, because they were very far from the real world of Satakal. And they found that it was too far to jump into the Far Shores now. The spirits that were left pleaded with Tall Papa to take them back. But grim Ruptga would not, and he told the spirits that they must learn new ways to follow the stars to the Far Shores now. If they could not, then they must live on through their children, which was not the same as before. Sep, however, needed more punishment, and so Tall Papa squashed the Snake with a big stick. The hunger fell out of Sep's dead mouth and was the only thing left of the Second Serpent. While the rest of the new world was allowed to strive back to godhood, Sep could only slink around in a dead skin, or swim about in the sky, a hungry void that jealously tried to eat the stars."
This sums it up pretty well. Sep as an evil or just foolish demiurge here represents Lorkhan.