In my quest to enjoy the game again, I decided to replay it in Lunatic with a gimped Avatar (+Mag, - Def) she was still useful but can't wreck everything in EP. I relied a lot more on actual teamwork than the usual Lunatic playthrough. I was using Stahl/Kellam pair until Cordelia arrived and then it became my standard Stahl/Cordelia thing, Frederick/Sumia (Fred's still going strong in Chapter 13 what), Cavalier Chrom/Avatar (Chrom being the good one in this pair), a rather spd screwed Wyvern Panne (Cherche came with better spd base, which is ridiculously improbable, I'm probably benching her for Cherche, which is weird), Libra, Olivia and I even used Virion at some point but had to stop due to deployment slots. It was rather fun. Problem is I bought Pokemon Y so gg FE13. Anyway, I recommend playing like this in Lunatic if you don't find it fun anymore:
-No deaths
-No grinding on anything.
-Avatar must have bad asset and bad flaw , preferably defense so it can't tank, ever.
-No buyable nosferatu, buyable Rescue optional, up to you if Sol is allowed.
It's a lot more challenging and fun this way.