I don’t have many/any proper AoS books myself, so I can’t contribute too much more information. They don’t make an appearance in the Soulbound Ulfenkarn City at the Edge of Death book.
But I can talk about White Dwarf 496. One of the oddities of the Cities of Sigmar heroes is the addition of the gargoylian companion. It’s listed as an Empowerment, but with no other text, other than what is on the card.
A gargoylian companion essentially provides a short-ranged attack at the cost of a 4+ die. There is a 50/50 chance of causing 0, 2 or 4 damage to the target. Those probabilites don’t add up, but you know what I mean.
The two oddest things are: why does it say “within 1 space” instead of “adjacent”, and what happens to the gargoylian after it attacks?
I have no clue why the range language is intentionally obtuse. My best guess is that, as a magical creature, the gargoylian can attack through a closed door just as a hostile can. Because, strictly speaking, models on opposite sides of a closed door are not adjacent to each other.
So what happens after this scaley buzzsaw materializes on the battlefield? I think they just take off again? Scamper or ephemerate, I guess they just take off. They seem to have the run of the Mortal Realms, also, they don’t have any other stats at all.
So… They’re an interesting little enigma. They’d be handy accompanying a melee only hero. We’ll throw one into the next game and see how it goes!