I know Gigantamax/Dynamax doesn't boost stats, but I just want to know.
Eternamax Eternatus functions similar to a Dynamax Pokémon in a Max Raid Battle. It can negate the effect of the player's Pokémon's Abilities and stat changes, cure itself of non-volatile status conditions, and use Max Moves in battle. After defeating it, the player will always catch it. However, it cannot create a protective barrier like Rank 3 and above Max Raid Battle opponents can. Additionally, it does not take increased damage from Behemoth Blade, Behemoth Bash, or Dynamax Cannon.
Eternamax Eternatus functions similar to a Dynamax Pokémon in a Max Raid Battle. It can negate the effect of the player's Pokémon's Abilities and stat changes, cure itself of non-volatile status conditions, and use Max Moves in battle. After defeating it, the player will always catch it.
However, it cannot create a protective barrier like Rank 3 and above Max Raid Battle opponents can. Additionally, it does not take increased damage from Behemoth Blade, Behemoth Bash, or Dynamax Cannon.
Eternamax (Bulbapedia)
It is similar in the sense that it makes the Pokemon larger and gives it a new appearance, but it's different for some of the reasons outlined above. Whether or not you consider it a "form" of Dynamax depends on how much you think the criteria above matter.
