Terra dei Demoni

I decide to go to the opponent's respawn using Dimension Door; I check if a Dimension Door to him is possible, the opponent doesn't know

It is not possible. The 1st page specifies the control restrictions. You must defeat the ГО both to reach the center and to reach the opponent.

update - it turned out that the opponent had already broken one ГО and was wiped out on the second. In this case, the ГО is considered broken, so you can pass in both directions, both with control and without it.