Do you need Barbarian invasion to use this mod?
No it is for rtw the demo is the full versian might be for BI.
Yep, like Hitman said, the demo is for RTW 1.3 and 1.5, the upcoming campaign version will be for BI.
Screenshots Competition! Win a Copy of Half-Life 2!
Vassal of gigagaia, Brother Knight to Professor420 & Jones King