“Unremarkable Form” in Pokémon means the standard, non-special version of that species. In this case, Unremarkable Form Sinistcha is the regular form that evolves from Counterfeit Form Poltchageist using an Unremarkable Teacup.

In simple terms

  • It is mostly a form distinction , not a totally different Pokémon.
  • The main difference is usually tied to which form it came from and, in some cases, a tiny visual detail like an authenticity mark.
  • For Sinistcha, the other form is Masterpiece Form.

Why the name sounds odd

Pokémon sometimes uses quirky form names to match the species’ theme. Here, the tea-pot/tea-cup idea is part of the joke: one form is “unremarkable,” while the other is “masterpiece.”

Example

If you catch a Poltchageist and it’s the common fake/counterfeit version, evolving it gives Unremarkable Form Sinistcha. If it’s the authentic/artisan version, it evolves into Masterpiece Form Sinistcha.

TL;DR: Unremarkable Form = the regular/common form, not the special authentic one.