Ishmael, (When he was calling himself Ba'alzamon" has several distinct characteristics. His firey eyes are the ones that everyone thinks of first, but he also has a particulat scarring pattern I believe that is described as "slashing" across his skin. Could this be a "price" of the true power? In addition, if you read the description of his scarring pattern and then read the description of the burn marks in the land in the alternate world that Loial, Rand & Hurin visit in TGH, they are very similar which struck me as an odd coincidence... A world where the TP was used so much that it took the price out in the land as well as the people? OK, maybe it just is a crazy theory. The important thing was the scarring that would either be because of Ishmael's great age or his use of TP.