Just like how Privateer Press has released Epic versions of Warlocks and Warcasters, showing how they've grown since their original release, they're now headed in the other direction. They will be coming out with what they're calling "Level 0 Warlocks" for Hordes, showing the characters before they came into their full power. The first one they're showing off is Barnabas the Conqueror.
From the article:
Some of the most powerful warlocks in HORDES had their rise to power far before the wars of the Iron Kingdoms spilled over into the wild places of the world. This Insider is the first in a series leading up to the release of five “zero-level” warlocks. The rules in these Insiders are still in playtest and are therefore subject to change.
As bringing these younger warlocks to life is all about revisiting events from their pasts, I think starting with Barnabas makes the most sense. Before almost all the characters currently living in the Iron Kingdoms were even born, Barnabas was uniting the strength of the Blindwater, fighting in savage contests of strength to prove he was the ultimate conqueror.