My main antogonist has a very sophisticated yet sarcastic tinge in his dialogues. How do write in a way where the reader would immediately grasp his sarcasm?
Its kind of hard to give general advice....sarcasm is just one of those things were you just know it (or you don't)...in general, its similar to irony, so they would say one thing when they mean the opposite, things like that, but again, it's hard to give advice on how to write it in general with no context. You're better off reading/watching sarcastic characters and seeing what they do/say. The most obvious and popular one is probably Chandler from Friends, so maybe start your study there?
You can indicate it through the other person's response, too. Most people react to sarcasm by becoming defensive or by coming back with hostility of their own. It's the same as conveying any tone or emotion. You are best off showing it through the entirety of the conversation, including the actions of the participants. Whatever you do, don't treat te reader like an idiot. Assume that the reader can pick up on the mood without guiding him or her through every grimace and raised voice. Keep in mind, too, that sarcasm isn't always immediately apparent to the person on the receiving end. If the recipient isn't sure, let the reader have a doubt or two as well.
In one of the series I watch, the main character Ayumu Narumi, once used sarcasm against his opponent when he only had two minutes to live. Not going into detail about how this came about. However, all his possibilities of survival had seemed to vanish, so in a last ditch effort he raised his hands to the heavens and pleaded that God save him. Although his tone was very sarcastic and stuff, his words sounded serious and needing. So his opponent believed he was actually praying, though his opponent didn't believe God could save him. Ultimately, he was saved within 2 seconds of his death and his opponent lost. But either way, those watching could tell that he was being sarcastic where as his opponent could not. It worked, because even those watching believed he had no hope left.
Sarcasm, like comedy, is an art. A well crafted retort is just that: well crafted. If you are not one to be sarcastic yourself, you may have to rely on the help of an acquaintance who is.
too true!... one must have the requisite wry wit, to do sarcasm well, just as one needs an innate sense of humor and the can't-be-learned ability to write [or act] comedy, to succeed at it...
There are times where context is not needed. "Yeah, I just love waking up to my neighbor's screaming guitar." Lewis Carrol had many opportunities to use sarcasm and didn't. Here is one I would have liked. the line in blue is my own. This is from Looking Glass. Perhaps for the first few times he is sarcastic you can use a tag, or make it clear by other's reaction, then after we get to know him, his sarcasm should come accross clearly.
^ If Lewis Carrol had made the irony explicit in instances like those, he would've ruined his book. The sarcasm/irony is so obvious there that even child readers can pick it up in the subtext, and Carrol calls attention to it all the more by having Alice ignorant of it. With humour, like with almost all writing, subtlety is your friend. Never overdo it, and never let it look like you're trying to be funny, because unless you really are, you'll look stupid. Terry Pratchett is the only example I can really think of (maybe Douglas Adams too) where the author is blatant and explicit in their attempts to be funny and get away with it because they really are actually funny.
