The task is activated when you attack a unit and kill it. To complete it, one must kill 10 units from other tribes. Retaliation counts, but Mind Bending does not.
The Gate of Power always follows a basic design of a tall gate with no door (similar to the Arc de Triomphe), however the decorations on the top and sides can vary considerably.
|Altar of Peace, Emperor's Tomb, Eye of God, Gate of Power, Grand Bazaar, Park of Fortune, Tower of Wisdom|