Being the first human to be willing to accept such a contract he was granted immortality, knowledge of the workings of the universe and a degree of reality warping.
- He taught man the earliest form of engineering with the construction of Stone Henge.
- According to legend he came up with the Symbolum Immortales.
He is referred to by Damien as 'The Man in the Tree' possibly in reference to his imprisonment inside a tree according to Arthurian legend. When Damien met him at an unspecified time period, Merlyn told him:
''The stars shall fade away, the sun himself
Grow dim with age, and nature sink in years,
But thou shalt flourish in immortal youth,
Unhurt amidst the war of elements,
The wreck of matter, and the crash of worlds.''