On death and other impossiblilites

Mars walked through the alien landscape, his mind (whatever that was) trying to call out for the trace and not getting much. His mind raced through the possibilities of where he was, how would he survive it once he grasped what this was. Everything was different save that he was on a planet and that it sustained existences and a myriad of other things that his mind was quickly assimilating and absorbing.
The other two following him at a distance Fijbold kept crouching down expecting to find what- legs (mandibles) to run on. He would constantly stumble into Kymat.

"Walker." Kymat said suddenly.

Mars stopped and turned back to face Kymat.

"Walker, you must end me." Kymat said.

"I cannot."  Mars said and knew it to be true.

"Walker." Kymat said, pleading. "Kill me."

Kill? Now there was a word that Mars recognized. He was the walker, the one whose designation had been to end many.

"I cannot." he repeated and turned away.

Kymat screamed in frustration and flung himself towards Mars, as he was about to collide with Mars, his own body rebelled against him and he missed more by the sudden spasmic shudder that sent him sprawling in the grasses.

"The exile won't allow me to end any of you." Mars said then continued walking towards the road.