>>15527475I, uh, haven't got around to breeding one just yet, since I've been hatching and trading for Kalos Dex completion (now just missing Gliscor in the "Seen" count, and no I'm not going to the restaurants because they all suck) so I can pick up that Oval Charm. Hunting for Taillow swarms and fishing for Politoed actually netted me two completely random 1-in-8192 shinies before I found what I was actually looking for...
Once I DO get around to breeding that SpanishInquisition-slash, I'm thinking Modest nature @ 6HP/252Sp.A/252Spe, with Autotomize, Flash Cannon, Shadow Ball, and Sacred Sword, holding either LO or Weakness Policy depending on how reliably I think I can get the WP boost. LO Sacred Sword, even totally uninvested with a negative nature, is powerful enough to OHKO most Tyranitar over 90% of the time, while also guaranteeing a 2HKO on Blissey even with Lefties.