In theory, as long as there is enough high-level Soul System Materials to create the "Thousand Faces of Soul," Mousie could infinitely create avatars and they could grow independently!
Do you have an invincible form?
Sorry, it's mine starting from now!
Do you have a Legendary Skill?
That's mine too!
Only 20-30% of the resources are needed. To be precise, it's about the Thousand-Face Origin removing the corresponding impurities and transforming it into a Perfect form, which could inherit most of the abilities.
Subsequently, with the help of Gary Smith's Taboo Secret Food and the Proficiency Panel, Mousie would soon be able to elevate the avatars to be on par with—or even surpass—the original.
As for the constraint of Thousand Faces of Soul only allowing Mousie to transform into one avatar...
It's not a problem at all!
Because Mousie also has a multitude of Mouse Incarnations.