Khorne capital building explained ?

[Revelation]

so as Khorne you can choose between Dimensional Cascade or Chaos Dreadhold capital building whats the diffrence ? they seem the same to me says can be converted into portal or bastion but idk what that means

[RecalledDread]

I think all Demon factions have this.

The Bastion gives Growth, and the Portal gives Corruption. They give a different unit as well.

[mcmendez]

Portal is more of a military oriented building and Bastion is more of a commerce (or infrastructure) oriented building. Portals reduce the cost of military buildings, reduce recruitment cost, add recruitment capacity and Portal recruit Bloodletters. Bastions reduce the cost of non-military buildings, provide control, corruption in adjacent provinces and recruit Marauders and Chaos Warriors.

[Comrade Pickles]

Look closer. The differences are clearly explained in the tooltips.