Emperor (Warhammer 40,000)
The Emperor was created in a ritual in 8,000 CE in Anatolia (what is now modern day Turkey) in which a large number of powerful human pskyers sacrificed themselves to create a defender of mankind against a coming darkness. Afterwards he wandered the earth in secret, learning much and subtly influencing humanity's development for the better. After the Birth of Slaanesh led to the age of strife, the Emperor decided that he needed to unify mankind under his rule.
Following the rebellion of Primarch Horus, the Emperor was forced to enter the Golden Throne, a special life-support system of his own design. His condition continues to deteriorate, however, and while still able to use his psionic powers to maintain the Astronomicon and enhance ordinary human psykers to be capable of astro-telepathy (telepathy over interstellar distances), he is only marginally conscious, at best, and the High Lords of Terra do all decision-making for the Imperium.
There are rumors that this life-support machine is also his bodyguard, and that it can transform into something with 10 times the power of one of the mighty Imperator Titans.