Kay is wrong too.
In languages with non-retarded writing kay would be represented as 'kei' and key as 'ki'.
Pokemon is pronounced po-ke-mon, but this is an uncommon sound in english it's the """A""" in care or air. These true Es are paired with an I/Y or an R but rarely by themselves. The closest native english speakers can get is using the E in bed and get which is similar but classified as its own sound under the IPA.
Oh, and here's another thing about the way english actually sounds.
You're adding an extra vowel without realizing it.
Poukiman (American) Poukimon (British)
The 'long' O is actually a diphthong of O + U, and if you ever learn a language cut your O short before it reaches that U. There is a short O but varies on the dialect.
Most American dialects lack this sound and just replace it with Ah / A and so they pronounce caught exactly like cot. However, like the example with E, the short O shows up for every English speaker when paired with certain consonants. In this case it's L and R. The examples would be Or and Old. If you listen carefully it sounds different from the diphthong of go which is a 'long' O.
TL;DR you're not speaking a language that pronounces anything normally in comparison to other major languages. So it doesn't matter.
Accented E in English is just an approximation of an actual E but this approximation is an EI diphthong. In shitty Spanish or French classes they will teach you to use the diphthong for this sound but it's actually a singular vowel without the I and native speakers of those languages can hear the difference along with the time it takes to pronounce two vowels instead of one.