The Mario Multiverse is enormous. It composes of Mario's universe, but it also includes all the parallel universes that are linked through cameos, mash-ups and cross overs
For example:
Zelda is part of the Mario multiverse
Link appears in an inn in Super Mario RPG.
The Legend of Zelda universe therefore exists within the Mario multiverse.
Sonic is part of the Mario multiverse
Sonic and his acquaintances appear in Mario and Sonic at the Olympic Games.
The Sonic universe therefore exists within the Mario multiverse.
Half-Life is part of the Mario multiverse
Gordon Freeman exists in the same universe as GlaDOS.
GlaDOS appears in Lego Dimensions, alongside Sonic the Hedgehog.
Sonic and his acquaintances appear in Mario and Sonic at the Olympic Games.
The universe of Half-Life therefore exists within the Mario multiverse, by way of the Lego and Sonic gaming universes.
Halo is part of the Mario multiverse
Master Chief comes from the same universe as SPARTAN-458.
SPARTAN-458 appeared in Dead or Alive 4, linking their universes.
Samus and Ridley appeared in Dead or Alive Dimensions, connecting the Dead or Alive universe to the Metroid universe.
Samus appears in an inn in Super Mario RPG.
Therefore Master Chief and the Halo universe all exist within the Mario multiverse, by way of the Dead or Alive and Metroid gaming universes.
The Witcher is part of the Mario multiverse
Geralt appears in Soul Calibur VI, linking The Witcher universe to that of Soul Calibur.
Link appears in Soul Calibur II, thereby connecting the Zelda Universe to the Soul Calibur universe.
Link appears in an inn in Super Mario RPG.
Therefore Geralt exists within the Mario multiverse, by way of the Soul Calibur and Zelda gaming universes.
Legacy of Kain is part of the Mario multiverse
Kain is a playable character in Lara Croft's Poker Party, linking the Legacy of Kain universe to Tomb Raider.
Lara Croft is a playable character in FINAL FANTASY BRAVE EXVIUS, linking the Tomb Raider universe to the FF:BE universe.
Cloud appears as a summon in FF:BE, linking the FF:BE universe to Final Fantasy VII.
Cloud is a fighter in Super Smash Bros for Wii U, linking the universe of Final Fantasy VII to Smash Bros.
Mario appears as a combatant in Smash Bros. Therefore the Legacy of Kain exists within the Mario multiverse, by way of the Tomb Raider, FF:BE, Final Fantasy VII and Smash Bros. gaming universes.
I hope these examples illustrate the idea that almost all high-profile gaming franchises, through crossovers, cameos and mash-ups, have all become part of the Mario multiverse.
My question is: What is the highest profile gaming franchise and/or character, that definitely isn't in the Mario multiverse?
For example:
Zelda is part of the Mario multiverse
Link appears in an inn in Super Mario RPG.
The Legend of Zelda universe therefore exists within the Mario multiverse.
Sonic is part of the Mario multiverse
Sonic and his acquaintances appear in Mario and Sonic at the Olympic Games.
The Sonic universe therefore exists within the Mario multiverse.
Half-Life is part of the Mario multiverse
Gordon Freeman exists in the same universe as GlaDOS.
GlaDOS appears in Lego Dimensions, alongside Sonic the Hedgehog.
Sonic and his acquaintances appear in Mario and Sonic at the Olympic Games.
The universe of Half-Life therefore exists within the Mario multiverse, by way of the Lego and Sonic gaming universes.
Halo is part of the Mario multiverse
Master Chief comes from the same universe as SPARTAN-458.
SPARTAN-458 appeared in Dead or Alive 4, linking their universes.
Samus and Ridley appeared in Dead or Alive Dimensions, connecting the Dead or Alive universe to the Metroid universe.
Samus appears in an inn in Super Mario RPG.
Therefore Master Chief and the Halo universe all exist within the Mario multiverse, by way of the Dead or Alive and Metroid gaming universes.
The Witcher is part of the Mario multiverse
Geralt appears in Soul Calibur VI, linking The Witcher universe to that of Soul Calibur.
Link appears in Soul Calibur II, thereby connecting the Zelda Universe to the Soul Calibur universe.
Link appears in an inn in Super Mario RPG.
Therefore Geralt exists within the Mario multiverse, by way of the Soul Calibur and Zelda gaming universes.
Legacy of Kain is part of the Mario multiverse
Kain is a playable character in Lara Croft's Poker Party, linking the Legacy of Kain universe to Tomb Raider.
Lara Croft is a playable character in FINAL FANTASY BRAVE EXVIUS, linking the Tomb Raider universe to the FF:BE universe.
Cloud appears as a summon in FF:BE, linking the FF:BE universe to Final Fantasy VII.
Cloud is a fighter in Super Smash Bros for Wii U, linking the universe of Final Fantasy VII to Smash Bros.
Mario appears as a combatant in Smash Bros. Therefore the Legacy of Kain exists within the Mario multiverse, by way of the Tomb Raider, FF:BE, Final Fantasy VII and Smash Bros. gaming universes.
I hope these examples illustrate the idea that almost all high-profile gaming franchises, through crossovers, cameos and mash-ups, have all become part of the Mario multiverse.
My question is: What is the highest profile gaming franchise and/or character, that definitely isn't in the Mario multiverse?