>>13548961Larvesta is dead weight. You'll probably have beaten the Elite Four by the time it evolves, plus you can catch one after the E4 at level 70, so unless you're set on training that thing, box it for now.
There are better Ghost-types than Cofagrigus (how do you pronounce that), and I say that because it is a defensive mon, so things will go quite slowly.
Archeops and Seismitoad are okay.
Musharna and Cryogonal are mediocre. I'd recommend getting a Solosis, and evolving it to Reuniclus, although I'm inclined to say that the only reason you even have one is because you couldn't trade to evolve a Duosion.