Munchlax - Base 5 speed, 85 Attack, 135 hp - Munchlax has the lowest speed out of all legible Pokemon, 85 Attack is pretty respectable, and it's 135 HP and 85 Sp.Defense makes it somewhat bulky, but it only has 40 Defense. Could potentially cause some chaos with STAB Return, maybe Facade, maybe EXPLOSION (TOP KEK), has Earthquake, Rock Slide. Does it have to be kalos bred? If not, it become soo much more viable with a diverse moveset which can utilize Superpower, Seed Bomb, Zen Headbutt, elemental Punches, Gunk Shot and it's chaotic.
Trapinch - Base 10 speed, 100 Attack - It's got awful 45 stats in everything else but it seems like something that can hit hard and fast when TR is up. He's also immune to intimidate with Hyper Cutter, and has access to surprisingly nice moves like Earthquake, Superpower, Crunch and Rock Slide.
Duosion - Base 30 Speed, 125 Special Attack - Like Reuniclus, I think Duosion will continue to be the awesome trick room attacker he is.
Doublade - Base 35 Speed, 110 Attack, and a shocking 150 Defense. I think it's pretty obvious.
Rhydon - Base 40 Speed, 105 HP, 130 Attack, 120 Defense - No questioning it either.
Gurrdur -Base 40 Speed, 105 Attack - He also has decent defenses with 85 HP and 85 Defense. Nice abilities with Guts/Sheer Force and of course has nice attacks. Hammer Arm, Rock Slide, Drain Punch, Mach Punch, Wide Guard, elemental punches (if can be non-kalos), Poison Jab.
Sligoo - Base 60 Speed, 83 Special attack, and pretty nice defenses at 68/53/113. Has a wide coverage movepool with Dragon Pulse, Muddy Water, Ice Beam, Sludge Bomb/Wave and Thunderbolt.
Pawniard - Base 60 Speed, 85 Attack, has Defiant to combat Intimidate, and a pretty decent movepool if anyone is familiar with it's evolution would know.
Zweilous - DAT HUSTLE OUTRAGE THO (In all seriousness, 58 Speed, 85 Attack, Hustle boosts his attack further but the accuracy drop can be deadly. Moves include Crunch, Elemental Fangs, Superpower, Zen Headbutt, but only has Outrage or Dragon Rush for moves of which the former is kinda bad in triples and the latter is already bad without the accuracy drop, wide lens might be needed)
Lampent - 55 Speed, 95 Special Attack, Like Chandelure I think it will be a good fire type for Trick Room and a potential setter.
Shelgon - 50 Speed, 95 Attack. He actually has a surprising amount of attack, given that he's a soccer ball with stubs. Moves include Crunch, Dragon Claw, Zen Headbutt, Fire Fang (if non kalos bred is okay), Rock Slide.
Piloswine - 50 Speed, 100 attack coupled with 100/80/60 defenses. Pretty nice, and has priority in Ice Shard for pinches.
Tyrunt - 49 Speed, 89 Attack, but he has strong jaws boost and has a nice amount of attacks with all kinds of fangs, EQ ad Rock Slide.
Inkay - 45 Speed, with only 54 attack, but can work similarly as Malamar by abusing Contrary Superpower and the same movepool and possibly having Feather dance Murkrow support. Can even use Topsy-Turvy if you feel like being gimmicky. Also a potential setter.