Encore is the way to go!
Infernape @ Life Orb
Ability: Blaze
EVs: 20 Atk / 236 SpA / 252 Spe
Naive Nature
-Quick Guard
-Close Combat
-Fire Blast
-Encore
This gives us a fast Quick Guard for Kangaskhan. It also gives us yet another way to donk Kangaskhan other than what we already have (I'm paranoid). Keldeo and Terrakion are more common as fast Fighting types with Quick Guard, but Infernape is the best bet in this case for being able to use Encore on the Subs, Protects, King's Shields, and Fake Outs. It also can hit Aeg harder than Keldeo or Terrakion can.
20 Atk Life Orb Infernape Close Combat vs. 0 HP / 0 Def Mega Kangaskhan: 354-421 (100.8 - 119.9%) -- guaranteed OHKO
252+ Atk Parental Bond Mega Kangaskhan Sucker Punch vs. 0 HP / 0 Def Infernape: 93-109 (31.7 - 37.2%)
20 Atk Life Orb Infernape Close Combat vs. 228 HP / 0 Def Kyurem-B: 354-421 (79 - 93.9%)
236 SpA Life Orb Infernape Fire Blast vs. 252 HP / 4 SpD Aegislash-Shield: 281-330 (86.7 - 101.8%) -- 12.5% chance to OHKO
(^conveniently combines with 252 Atk Aerilate Mega Pinsir Feint vs. 252 HP / 0 Def Aegislash-Shield: 25-30 (7.7 - 9.2%) to offer a very good chance at getting the KO that way through King's Shield if we want it.)
Since Kyu-B is already dealt with pretty well by Conkeldurr, I decided to focus more on Aeg, which meant going for Special Attacking prowess. Luckily, since the Kanga spread being used is fast, rather than bulk, we can still OHKO it with Close Combat with only 20 Atk EVs and Life Orb. Kyu-b gets donked pretty hard too. Encore can screw all 3 of the opponent's mons over, as mentioned above. Quick Guard will also provide some backdoor protection against Talonflame and Thundurus, among others.
Plz comment on the set. I feel Protect over Quick Guard might be better, but then Talonflame is a huge threat to the team.