Evangelion Mark.04
The Nemesis Series are a group of artificial Angels[Source needed] that first appear in 3.0. They are notably different than the Angels of the first two movies, containing Core Blocks instead of individual cores. They appear to be inorganic in nature.
Purpose
While the Angels had a clear goal to reach Lilith or Adam, the Nemesis Series do not seem to have a clear objective. They have appeared during the salvage operation for Unit-01, and also when Shinji arrives on the AAA Wunder. It is unknown exactly what their aims are, if any.
History
It can be inferred that the Nemesis Series did not exist prior to 3.0. However, precisely when they appeared is a mystery. Misato delivers the line, "They're back" when referring to the Nemesis Series, but she could merely be talking about their presence during the salvage operation. Other interpretations of the line could be that they existed prior to both the launch of the Wunder and the salvation of Unit-01. It is currently unknown where the source of the Nemesis Series is, but there is speculation that they were created by Neo-Nerv.
References