{3}, {T}: Tap target creature. Gain control of that creature instead if you control artifacts named Scepter of Empires and Throne of Empires.
If any of the named cards stops being an artifact, it won’t be considered by these abilities.
If you control artifacts named Scepter of Empires and Throne of Empires, the targeted creature won’t be tapped. You’ll just gain control of it.
Whether or not you control the correct artifacts is determined when the ability resolves.