Multiverse of the Eternal Champion

The Great Wheel encompasses the entirety of the Universes visited by the Eternal Champion.  These worlds are accessed by the Moonbeam Roads.

The Moonbeam Roads

The Moonbeam Roads are the ethereal pathways through the Multiverse, leading between universes, from world to world. The roads pass through the Higher Worlds, and run between the universes. A traveler upon the Moonbeams can percieve the entire Multiverse around them.
The Moonbeam Roads are a manifestation of the Holy Grail and therefore also a manifestation of the Runestaff and the Spammer Gain. An adept of the Game of Time can find them easily. Some people, like Elric, can find them unconsciously. Stormbringer has shown the ability to cleave a pathway to the Moonbeam Roads.  The greatest known navigator of the Moonbeam Roads is the Rose Von Bek.
Very few people can find the Moonbeam roads.  One Torillian to do so was the Drow Assassin Quietus N'a' Lespit, who stole Stormbringer from Elric of Melnibone for a time.  The Company of the Cold Peaks aided Elric of Melnibone in defeating Quietus and getting Stormbringer back.  Quietus in his absolute arrogance, ruined most of the city of Yuann in Sembia with the power of the Blacksword.

Manifestation

Blackrazor is an Object of Power for the Multiverse.  
A manifestation of the Holy Grail has not yet been found on Toril.
Elron the Champion, General of Evermeet is the Eternal Champion of the Forgotten Realms.

Localization

The moonbeam roads can be stumbled upon but very few people know how to find them.  Portals to any point in the Eternal Champion multiverse  are common.  Sigil has doorways to many places including Tanelorn itself which exists on many worlds.