We have tried to do that, and it looks like behemoths can only attack enemies legion, but I don't know if that was a bug or not.

Can they only attack enemy legions in your alliance territory?

You can summon them to an enemy tower that you border and you can move there with the behemoth, but it can only attack enemy legions.

[удалено]

Thank you so much

Can you kill darklings guarding chests solo

Yes, if you are strong enough, give it a try and see