It'd help if you mentioned natures since you're using, but I'm going to base this on where the strongest stats are in. Anyway, for Houndoom, ditch Solarbeam because you're leaving yourself open for a turn, and unless you use Sunny Day just for that one Pokemon it sort of doesn't have a point. Embargo can be useful in some cases but not really against the Elite Four because switching is probably going to occur, so you could always stick Sunny Day on it, but really, Houndoom's defences aren't that great so you're better going for full out STAB. But yeah not really sure what you can put on either of those two, I just suggest not to use those attacks on it. :x
For Raichu, again, defences aren't that great so setting up with agility on a 100 base speed Pokemon doesn't really have a point, especially in-game and if its main point is to set up light screen then you're better off with thunderwave if thunder fails or something.
As for Jolteon, go for either tbolt or thunder instead of shock wave & thunder fang, since if you want both, then you have tbolt for 100% accuracy and thunder to test your luck against tough foes.
For Empoleon, its defences aren't that bad so you could start with that and use SR so it can at least take a hit and maybe EQ to cover your electric weakness even though it'll be noticably weaker. Also, change Waterfall to Surf because Waterfall is Physical and you want sPA on Empoleon.
Either way that's about all imma comment on, good luck with Cynthia though!