Here's why:
* Miracle Fusion's Requirement: Miracle Fusion requires you to "Tribute 1 'Elemental HERO' monster" to use its effect.
* Neos Alius' Status: Neos Alius being in the Graveyard means it is not on the field and therefore cannot be tributed.
To use Miracle Fusion, Neos Alius would need to be on the field (either face-up or face-down) so it can be tributed.
However, there are some ways to potentially get Neos Alius onto the field from the Graveyard:
* "Elemental HERO Neos Alius" Effect: Neos Alius' own effect can bring it back to the field under certain conditions (usually by returning an "Elemental HERO" monster from the Graveyard to the hand).
* Other Cards: There are other cards in the game that can bring monsters back from the Graveyard, such as "Call of the Haunted," "Monster Reborn," or even "Return from the Different Dimension" if Neos Alius is a "HERO" monster.
Let me know if you have any other Yu-Gi-Oh! questions!