Grammar and Word Usage for "imperil"

The Japanese language favours passive constructions and other phrasing where it's not directly stated who the cause of the action is. This lends some insight into why the translator might have chosen 'imperil'.

Your 'imperil' example sentences aren't grammatical, either those from the community which you provide, or those of your own concoction. (I prefer the community examples, for what it's worth. They feel more natural and your improvements make them more stilted. Sorry.) This is a specialist, nonstandard use of the word that works in one very specific context - this particular game - it assumes knowledge of that context and is not standard English. Correcting them is a fool's errand and, likely, a thankless task anyway. (Do you perhaps think people will adopt your 'improved' style? Hopefully, probably you don't... and this is all just to satisfy your own curiosity about the word.)

You might consider this vocabulary as some sort of attempt at stylising the English, as others have suggested - a deliberate idiosyncrasy. Without seeing the context I can't be sure, but I would actually suspect dodgy translation as the root cause, rather than style. Mistranslations abound in English rendered from Japanese (by native Japanese speakers) and Japan doesn't seem to care much about it. Odd words plucked from dictionaries and shoved into contexts where they don't belong are not uncommon. This isn't restricted to video games and goes far beyond all your base are belong to us.

For whatever reason, these 'imperil' example sentences are all built on something that is idiosyncratic, stylised, specialist, nonstandard or just plain wrong (albeit understandable). Your gaming community has adopted some natural-sounding jargon that works - does it matter if it is nonstandard?

Regardless, I wouldn't go throwing 'imperil' around in everyday conversation. It's not a word of the right register for that. (To get a better sense of its usage, you can trawl through the example sentences of reputable dictionaries at your leisure.) Plenty of good alternative words have already been suggested in answers and in comments, if you want to standardise your sentences to take them out of their specialist context.

However, there is no spell to fix this usage of 'imperil' for you. Sorry.

The question is itself flawed inasmuch as it asks for correction on something that is nonstandard usage, so there really is no solution.

As someone who teaches/tutors language (mainly English), let me try to give a 'real world' answer that seems most correct to my ear. Most commonly in modern times, if at all, you'll hear 'perilous' used from the base noun 'peril' to make the adjective. But, both imperil aned peril are a bit antiquated words that aren't really used in common speech anymore. Instead you'll hear that you are in 'danger' or any other more common synonym.

As for the game using the word 'imperil' for what it did, it could just be a poor translation in attempting to take the direct style of wording they're using in Japanese to try to remain faithful to the mood of the game (but often in times like this, it ends up being awkward.)

I don't believe I've ever actually taught either of those words or any forms of them to any student I've worked with, which are mostly exclusively looking for speaking language skills in modern day, often for business or just 'friendly' conversation.

Bottom line, it seems like a clear case of attempting to go with perhaps period-appropriate vernacular to give it a more immersive feel; that or what is being perceived as an 'authentic' representation of the fantasy world in the era it's taking place in.

Here's the golden rule really, especially since this is a game: If it's fun and helps you get into the feel of it, then it's not wrong. It may be awkward, and it may not be what was really spoken if this is a game based from a realistic time in Japan, but, it's a situation of take it how it is.

But as for your sentences, and really all the uses of the word up above, you can dig into some old book and glance at the style of speech, and put it under a microscope with a dictionary while making sure the latin that it comes from all matches up as if it were a test, but none of it in real context you would really consider 'correct' as it's not natural at all.

If it must be used for the sake of the game, then the most natural thing that can be used would to remove imperil and use the phrases 'place in peril' or 'put in peril'.

"I will place him in peril with fire."

Just for something to glance at to see the initial use of it, followed by the rest of ot the article using the natural words that have been in place for quite a long time now:

http://www.cbsnews.com/news/weather-hurts-gulf-oil-fight-wildlife-in-peril/

But, again, I believe this honestly is a simple case of either poor direct translation, or someones overuse of a thesaraus which is pretty common when it comes to trying to 'sound the part' for something of this nature.

Hope that helps, it's all I can offer as my experience from teaching and also having experienced games just like that to be honest (I think Way of the Samurai for PlayStation had awkward dialogue at times like that.) Sorry if this was totally the wrong direction of what you were looking for.

Better for me to at least try to help out rather than just ignore an interesting question completely! Cheers!