I can't really think of anything that learns Discharge that has any sort of synergy with it besides washing machine/oven, which is shit on by Ttar. Especially since other Thundurus-T and Ground types will be common and you may not always have one of these out, I don't think Discharge is a very good move. Lightningrod Zapdos would be a better choice to attempt to abuse that with, but it's not out yet and likely won't be this season. If survivability is an issue, you can try to go for good prediction and switch into an enemy's electric attack.
EDIT;; Forgot about mixed Eel, P2, and maybe Klinklang if you're insane. It does outrun Mamo and resist both of Tar's STAB, but you need to be boosted to beat Terrakion.