What lore do you ignore?

[Cleretic]

You know how the Ys franchise is pronounced, yes?

Wrong, and bad choice of evidence anyway: Ys is written イース, which is roughtly 'isu' with that long 'ee' sound.

The Japanese Y sound is one of those consonants that only exists with trailing vowel sounds, but is usually with that sharp, shorter 'Y' sound; 'Ya', 'Ye', 'Yo', and so on. Y'shtola and Y'mhitra's names specifically starts with the 'Ya' character, but their names are in katakana so it's treated as a loan word.