"True Believers"
The Eternals are brought to Madripor by the manifestation of a Uni-Mind, but unlike any the Eternals have conjured themselves. This one drains the consciousness from humans, leaving their bodies to slowly die, and the phenomenon is spreading globally. They find behind it the Young Gods, a group of 12 gifted humans who had been adapted by the Celestials (see Thor (Vol 1) #300), who are attempting to drain every mind on the planet to create a new Celestial.
"The Young Gods Fact Pages"
"The Fourth Host" reprints Eternals (Vol 1) #7.