Hey, this is a really nice team you have here.
I can see Magmortar being pretty annoying to this team, mainly because nothing really wants to switch in on it, and there's a pretty big possibility that it could come in before Stealth Rock. Fire Blast can decimate Serperior and Haunter, while Focus Blast beats Lickilicky, your own Magmortar and Bastiodon. Haunter can't OHKO with Shadow Ball, although it can ease things with Trick [you'll have to lose something in the process of getting Haunter in, though], while Samurott only does 56.57% - 66.67% to 24 HP Magmortar with Aqua Jet before being KO'd with Thunderbolt. I think you could probably just play around Magmortar, however, by getting SR up fast and pressuring it with your own Magmortar, but it will still end up doing significant damage to the team. Overall, I think giving Samurott a Life Orb is perfect insurance against Magmortar, as LO Aqua Jet does 72.73% - 85.86%, which has a huge chance to OHKO after SR [81.25%, to be exact]. Also, you don't have to switch Haunter for something that beats Quagsire if you use Arbok, since Arbok has Seed Bomb.
Lum Berry->Life Orb
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