Slash Return with Shadow Claw on the first set. Return allows you to do a lot more damage against Pokemon such as Musharna, Duosion, Exeggutor, Lickilicky, Vigoroth, Garbodor, Weezing, Amoonguss, etc. (Without Return, a lot of these kills are a lot harder to achieve or impossible. Musharna isn't a kill but it's pretty close) and you do a lot of damage to Haunter with Seed Bomb anyways. Missing out on Missy sucks, but you can beat NP Missy and there's always Pokemon such as Skuntank to Pursuit kill it.
Also, in my opinion Rock Smash should be moved to OO. All it hits is Bastiodon and Probopass and you do a lot less damage against more threatening stuff such as Golem, Regirock, and Quagsire. Probopass can't really do much back and Bastiodon can only Roar you out.