NHF – new heroes for Heroes V 3.1.

Can we come up with descriptions and names for the abilities of already created heroes?

If you're not too lazy, then no problem. We can change it if it's better. The ability names are already a bit far-fetched.

What prevents us from giving this hero the "Summon Il-Hijra" ability with a corresponding city?

There is no such lock. It simply summons an empty spell, which is named "Summon Il-Hijra," which triggers a script that moves the city, and even then, the script is not very flexible, meaning it's only for a specific map.

Added 1 minute ago

In what sense does it "work"?

Are you testing your scripts on a map or not? It looks good at first glance. But just in case...