@EDS_Sora Indeed, and it also fails to take into account the phonetics that exist in other languages that are not possible to re-create with Katakana. That's why the difference between L and R, M and N, V and B is a big problem when learning, in this case, English.
@EDS_Sora There's also the ending of syllables on consonants. In Katakana, every letter is a syllable, so every syllable about from "n" ends with a vowel. So English becomes Ingurishu. Valet becomes Bare. Silly becomes Shirrii. And like you said, Cancel becomes Kyanseru.