If I play {Everlasting Torment} in EDH, does the commander damage turn into wither? Or nothing happens since it damaged the player?
Hopefully a mod can put this in Rules where it belongs. To answer your question:
Wither specifies damage dealt to creatures only. Damage dealt to players resolves normally.
702.79a (http://imtgapp.com/forum/index.php?action=imtg;area=rule;number=702.79a): Wither is a static ability. Damage dealt to a creature by a source with wither isn't marked on that creature. Rather, it causes that many -1/-1 counters to be put on that creature. See rule 119.3.