**Ended
As the title states, solve the riddle to win a prize. Once solved, message me the answer. First 10 right answers win a prize! There is a big clue on my page, it's located on the "right".
Upon my right arm's canvas, a saga etched in ink,
From frozen peaks where ancients drink.
It cripples the watchman, halts his patrol,
A foreign shard in the joint below.
What am I?