Becoming Immortal

Before his mutant powers developed he was a sailor for the Spanish Armada several hundred years ago. On one journey he succumbed to scurvy an was buried when the ship reached land. A few hours later he woke up discovering his immortality.

Externals

Over several centuries, Gideon was able to amass a vast personal wealth. He also encountered and allied himself with the Externals. At the end of the 20th century the group began seeking their newest member Sunspot. He had known Sunspot for many years after dealing with his father a wealthy Brazilian businessman.Gideon had Roberto's father killed, and approached the boy, telling him he needed to take over his family's business. He took the boy under his wing and tutored him until it was found that Sam Guthrie Cannonball not Sunspot was the new External they were seeking. Gideon then gave Sunspot over to a scientific lab so that they could experiment on him, they augmented his powers(almost killing him in the process).Gideon also clashed with the group of young superheroes known as the New Warriors.

Death

Gideon was slain by fellow External Selene when she drained the life force from him and the rest of the Externals, so that she could sustain her everlasting life.

Powers

He had the ability to mimic the abilities of nearby persons, and since he was an External, he was granted with limited immortality, only ended if he was decapitated, or a very damaging Virus(Legacy Virus), and obviously by having his life force drained.