Quoted By:
Fusion has been done before, but never as an in-battle mechanic. This is how I'd imagine it functioning in a battle:
>Send your main Pokemon out, and in the Attack menu you have a "Bond" option
>Option may be intrinsic, like DMax or Tera, or you have to hold an item, like Megas or Z-Moves
>When you pick "Bond" you are taken to your Party menu. From there, you pick which Party Pokemon "Bond" with the Active Pokemon
>ANY Party Pokemon can bond with ANY Active Pokemon
>While Bonded, visually, the Active Pokemon has a ghostly aura of the Party Pokemon its Bonded with
>Switching out the Active Pokemon while it is Bonded with a Party Pokemon breaks the Bond
>Alternatively, you may be unable to switch out the Active Pokemon while it is Bonded with a Party Pokemon
As far as how it works mechanically:
>The Active Pokemon inherits the traits of the Party Pokemon
>The Active Pokemon gains the Party Pokemon's ability, allowing it to have two abilities active at once
>If the Party Pokemon being Bonded has any higher stats than the Active Pokemon, the Active Pokemon inherits it's stats
>HP however acts differently, where the HP both Pokemon have at the time are added together
>Any HP damage taken once Bonded gets evenly divided across both Pokemon
>If HP reaches zero while Bonded, both Pokemon faint
So for example, you have a Salamence on the field and a Metagross in your party.
Salamence's Stats
>Atk = 135
>Def = 80
>SAtk = 110
>SDef = 80
>Spd = 100
>Ability = Intimidate
>HP = 200/331
Metagross's Stats
>Atk = 135
>Def = 130
>SAtk = 95
>SDef = 90
>Spd = 70
>Ability = Clear Body
>HP = 364/364
When you Bond the Party Metagross to the Active Salamence, Salamence's stats become:
>Atk = 135
>Def = 130
>SAtk = 110
>SDef = 90
>Spd = 100
>Ability = Intimidate AND Clear Body
>HP = 564/695
However, like with Dynamax and Gigantamax, there are select pairs of Pokemon that get a completely unique model
These are called "Fused Pokemon", such as pic being a fused pair of Lucario and Zoroark
