Leman vs. Magnus

Thunder banged in the midnight sky, and heaving earthquakes ripped ever-widening cracks in the ground, toppling what few structures of Tizca remained standing.
The epicentre of this destruction was Magnus and Russ, and Ahriman watched the two titans wrestle with the bitter enmity reserved only for those who had once called each other friend. Such a contest of arms was the most desperate thing Ahriman had ever seen. He wanted to rush forward and remind them of their former kinship, but to intervene in such a planet-shaking conflict would be suicide.

A Thousand Sons pg. 402