| Spoiler warning!|
"You're joking right? The Black Legion wants to come back and destroy Ulvania? They Can't! That's where I keep all my stuff!"
During the Second Kativan War, demons poured out of the portal created by Kativa. The most powerful demons were the Archdemons, mere generals to Kativa. Supposedly, if a big enough portal is opened, the entire Black legion would emerge, consuming Ulvania and the Realm of Magyk in fire and demonic magyk. In order to create the enormous portal, 5 Gatestones would be required, and it would still be unstable, however, as Kael finds out in Realm of Magyk, Kativa wishes to use the plentiful demonic gatestones in Daemonrealm to keep the portal stable.
The Black legion is a massive horde of demons from Daemonrealm. The Black legion is supposedly the unified army of the demons. According to some hypothesis and demonic references, there are far more powerful demons than the most powerful, the Archdemons, in Daemonrealm.
Should the black legion enter Ulvania, it is doubtful that anybody would survive.