Thunderstone = a Finnish band. takes part in our Eurovision trials this year.

Johto = a Finnish word meaning 'lead' (as a noun based on the werb 'to lead', 'johtaa'). Pronouned quite differently from Japanese 'jouto/jooto'.

Kanto = a Finnish word meaning 'tree stump'. I think it is pronunciated with two os in Japanese though.

Getto = Ghetto, Jemish quarter, cf. Japanese Pokémon term 'Getto da ze!'

Pika = a suffix in Finnish language, meaning 'fast' or 'quick', for example, 'pikaruoka' = 'fast food', 'ruoka' being the word for 'food'.

Teppo = a Finnnish boy's name [Teppooo (Teppouo) = Remoraid's Japanese name]

Paras = a Finnish word meaning 'the best'.

Minun = a Finnish word form meaning 'my, mine', the stem being 'minä'.

Pippi = A Swedish fairy-tale figure Pippi Lĺngstrump, Clefairys Japanese name.

So you can say like this in Finnish:

Ash johtaa johto-liigaa.
Ash leads the Johto League.

Paras on paras!
Paras is the best!

Minun Minunini!
My Minun!

Tuo Minun on minun!
That Minun is mine!

Tässä ovat Minun, Paras, ja minun paras Pokémonini, Parasect!
Here are Minun, Paras and my best Pokémon, Parasect!

Can you add more? Or can you invent more word plays like those, if you can do it in English I could perhaps translate them!