It is a longer, slimmer sabre than Eric carried, the silver pattern blade forged on the steps of Tir-na Nog'th itself so legend has it. Against creatures of supernatural origin, it is as deadly as it is pure; they cannot recover from wounds dealt with it. She has also been used to traverse the gaps in a broken pattern and thus allow her wielder to reach the centre.
It is fitting that it now belongs to Mordred, Prince of Avalon and sometime protege of Corwin himself - the first master of Grayswandir, if she is ever truly mastered. A man who seems to have paralleled Corwin with uncanny accuracy in his trials and tribulations.