When having multiple Helms of the Dominator, selling one of them kills the dominated creep
Helm of the Dominator is restricted to one creep per player. However, when having multiple helms, and losing one of them (destroying or selling it), the dominated creep dies, despite still having a helm. The game does not check whether a helm is still present or not, it kills the creep as soon as a helm owned by the player gets lost.
This proves to be a severe issue for Arc Warden
. Since it is restricted to one creep per player, and not per hero, his creep always dies whenever he resummons his Tempest Double
. This is because whenever resummoned, the double's inventory gets cleared and it copies Arc Warden's items anew. This clearing, which also removes/destroys the double's helm, causes the creep dominated by Arc Warden to die.