Before we look into the explanation of 吃了, we need to acknowledge that
translations, unless done by professionals, most of the time will sound/look weird even/especially to native speakers.
Now for the 吃. Like Tang Ho said, 吃了 in here means took.
You can see similar usage in 吃我一拳 which means take my punch.
The rest of the sentence doesn't really make sense. A little advise, if you want to improve Chinese reading skills, read something that's written in Chinese, not translated into Chinese.(I've done Eng-to-Ch translations before, and some things just can't be translated perfectly into normal Chinese(grammar-wise) without spending a ton of time. A manga light novel just doesn't sound like it can afford the time and money it needs to be translated.
A fun fact: Translation style writing/speaking is something we can pretty easily recognize. Sometime when writers want to create a foreign character without writing in another language, they will use this style so that their 'foreign-ness' pops.
Note: If you really want to read Japanese novels, read those that are super famous so you can get better translations.