Phyrexia
Phyrexia is an artificial plane of entirely mechanical "life" created by an ancient planeswalker. Little is known of this planewalker, aside from the fact that he enjoyed assuming the form of a dragon. This world was not so different from Mirrodin until Yawgmoth arrived. Yawgmoth, and the remnants and descendants of the phthisis-inflicted Thran whom he "saved", lived on this plane.
Structure of Phyrexia
The plane consisted of nine nested spheres, each with its own purpose and, often, mechanical ecosystem.
First Sphere
First Sphere of Phyrexia is a mechanical parody of life. It's covered by artificial jungle bedewed by oily rain. It's home of few forms of dragon engines and many others mechanical animals simulating true life.
Second Sphere
Third Sphere
Third Sphere is filled with metal pipes creating space distortions that prevents planeswalking to lower spheres.
Fourth Sphere
Fifth Sphere
Fifth Sphere is the ocean of glistening oil used by Vat Priests of Fourth to breed newts.
Sixth Sphere
Seventh Sphere
The Seventh Sphere of Phyrexia is an eternal furnace of flames used to both power the plane and punish those who have failed Yawgmoth. Gix is the only Phyrexian known to survive the Seventh Sphere
Eight Sphere
Ninth Sphere
The Ninth Sphere is the control center for all of Phyrexia. Up until the Invasion, it was where Yawgmoth resided in plotting his eventual takeover of Dominaria.
Phyrexian People
Militarization
Invasion of Dominaria
Post-Invasion
Map of Phyrexia
Note
The forums in Phyrexia.com imitate the 9 spheres of Phyrexia.