How did Tam come to have a heron-mark sword?
It was given to him by the King of Illian during Tam’s service with the Illianer Companions. We do not know what he did to become a blademaster.
What Maria says here is what RJ said (reported by Erica Sadun in 1994 ). In The Gathering Storm Chapter 47, Tam tells Rand that he became a blademaster by killing a blademaster in front of witnesses. The general fan explanation is that Tam refused to take his sword, but was essentially forced to take it by the King of Illian.
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