There are a few different words in Japanese that can be used to mean "transform." The one that, I think, gets translated to "deformation" is usually 変形 (
henkei). The symbols literally mean "change shape." The
jisho definitions for this word have both "deformation" and "deformity" as possible usages. The first kanji, 変, can also mean "strange/unusual," which is probably why it can be used in those different ways. (It's the same kanji used in words like 大変,
taihen, "great/unusual/terrible", and, yes, 変態,
hentai, which can mean "pervert" but it can ALSO mean "transform".)
Another common word, 変身,
henshin, means something closer to "change body," and it's what heroes like Kamen Rider shout out when they dramatically put on their costume. A machine turning into another machine, therefore, would use the word that could also be treated as "deform."
I'm not literate in any form of Chinese at all, but I'd guess since some of the kanji carry over between languages, it's probably a similar deal.