Nobody can contest the supremacy of Arc Warden in Dota 1 when it comes to the skilled cap heroes. In standard play, he can control dozens of units across the map. A correct item and skills build is crucial, but it is hard even for experienced players when they have so many options. It is one of the most difficult heroes to master, but because it is one of the most useful, many people prefer to play it instead of any other.
Arc Warden is unique because of his ultimate, the Templest Double, which creates a clone of the hero. The clone has the same abilities and many of the heroes of the original one. If the game goes into later stages, the team having Arc Warden wins. However, keep him safe before having one or two major items, as he is not so great at the beginning of the game.