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I believe that Grendel did all that because he does not want the king to think that he is being merciful. He says it himself - "...killed the two guards so I wouldn't be misunderstood and left".
Answer:
He is legally blind and wears very thick glasses. He has no peripheral vision. He believes that he was blinded by looking into an eclipse of the sun. The truth is that Erik spray painted him in the eyes when Paul was four or five years old
Explanation:
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