For example: there’s a mistranslation from the scene from CoD that Makarov mentions: “Remember - no Russian” but instead was rewritten as「殺せ、ロシア人だ」(they basically rewrote the entire line as “Kill 'em, those Ruskis” which defeats the impact from the original, like WTF does that have to do with anything. The 日本語 “translation” is shit).
Even in languages similar to English (like Spanish, French or German): can translated dialog either from dubbing or subtitles still suck when you know what the original one said? The thing is, there are cultural nuances and slang to take into account (and lip sync when speaking about dubbed versions, as each language has different animations).
Final Fantasy VII has the classic mistranslation right at the start when Cloud says “Barret, be careful! Attack while its tail is up! It’s gonna counterattack with its laser!” when the complete opposite is true and it should have been translated more as “Watch the tail! You don’t want to be hit by that laser!” (i.e. DON’T attack while the tail is up).