Why did Ain's name change to ein?

I think another translator came along and translated it differently

Tbh I didn't even notice it until you mention it Σ(っ°Д °;)っ

If this is a Korean comic then they probably spelled it the way Koreans spell English words and names according to how it's pronounced. Ain is pronounced as "eyn" making the "A" sounds like "E", but they don't have a letter that would specifically sound like the letter "Y". They only have "ya", "ye", "yo", "yeo", "yu". So to make up for it, they'll use "i" after "e" to make the "ey" sound, like this below

"에이" = ei (sound, read)
ㅔ = letter e
ㅣ = letter i
ㅇ = silent when placed before vowels, "ng" when placed after vowels, putting it before vowel letters is necessarily for spelling purposes

(I'm not credible enough to explain so it might still be confusing but I tried my best lol. Only learned Hangul for Kpop lyrics so hehehehe hope it somehow helps lol)
⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄