text: Since Planar Nexus has the subtypes Urza's, Mine, Power-Plant, and Tower, it will satisfy all of the requirements for the abilities of Urza's Mine, Urza's Power Plant, and Urza's Tower to add additional mana. For example, if you control Planar Nexus and Urza's Tower, the ability of Urza's Tower will add {C}{C}{C}.