How do you get the berserker armor in aqw

The Berserker class can be found in the upgrade shop in Battleon.
The Beta Berserker class is RARE and was only available during beta testing.
The Undead Berserker armor can be found in the evil shop in Shadowfall.

Note: The Undead Berserker Armor is only available to evil players and costs 1,000 ACs.