This reuses the existing Unknown map for this raid zone:
Code:
<ImageStyle Name="exp22_dun_unknown_raid_02" displayname="The Unknown: Voidborn Emergence [Raid]" zonerect="-1616, -1436, 2470, 1542">
<ImageFrame Source="images/maps/map_exp22_rgn_unknown.dds" SourceRect="0,0,800,600"/>
</ImageStyle>