I'd say try training Houndour, train it to a Houndoom (it evolves at level 24) and get it to learn a few dark moves. It learns Bite at level 16 and Beat Up at level 25, and Feint Attack at level 35 as a Houndoom (or 32 if you keep him as a Houndour until then). It might help you out. Herdier learns Crunch at level 24, plus it's immune to ghost type attacks, so you could consider training that one as well.
You could do that and it might work out well, but I haven't tried out using these pokémon myself, so please take everything I said with a grain of salt! I just hope it might work out in your favor :V