I have no idea what I want them to look like at the moment. Their playstyle, typing, and abilities are meant to reflect each other.
Terracer
Type: Psychic / Ground
Ability: Renegade* / Mold Breaker
Renegade - Type resistances by this Pokemon are increased by 25%. Ground-type moves deal supereffective damage.
Base Stats: 70 / 120 / 60 / 140 / 60 / 100
Offensive Movepool - Psychic, Psybeam, Shadow Ball, Energy Ball, Aura Sphere, Earthquake, Earth Power, Psycho Cut, Signal Beam, Thunderbolt, Thunder
Support Movepool - Agility, Calm Mind, Confuse Ray, Night Shade, Bulk Up, Teeter Dance, Psych Up, Toxic, Will-o-Wisp, Hypnosis, Thunder Wave, Power Swap, Dragon Dance
Terracer is clearly a sweeper by definition. 120 / 140 / 100 offensive stats are not bad at all. However, given Psychic-type's poor coverage it's going to have to rely on its secondary Ground-type. Renegade softens opposing resistances by 25% which can be helpful, but also grants an unwanted weaknesses to the common Ground-types. Mold Breaker opens other opportunities for sweeping, allowing hits on Bronzong and the Rotoms. Defensively Terracer is poor. Being Psychic / Ground suffers weaknesses from Dark-, Ghost-, Ice-, Grass-, Water-, Bug-, and Ground-types, with only one immunity and hardly any resistances. Stealth Rock isn't a problem, but lack of a recovery move and the above problems on defense will surely hurt it.
Terreciel
Type: Dark / Ground
Ability: Life Aura* / Mold Breaker
Life Aura - Neutral hits dealt to this Pokemon are decreased by 25%. Fighting-type moves deal 50% damage.
Base Stats: 140 / 60 / 100 / 60 / 110 / 80
Offensive Movepool - Dark Pulse, Crunch, Shadow Sneak, Night Shade, Earthquake, Earth Power, Aura Sphere, Seismic Toss, Shadow Ball
Support Movepool - Agility, Amnesia, Calm Mind, Confuse Ray, Night Shade, Teeter Dance, Psych Up, Toxic, Will-o-Wisp, Hypnosis, Taunt, Recover
The defensive compliment. Dark / Ground isn't an amazing defensive typing, but it isn't terrible, either. Immunities to Psychic- and Electric-types are nice, while Life Aura shifts Fighting-type moves to a resistance. Life Aura also softens up all neutral hits, making switching in easy. Recover gives Terreciel longevity as well as a reliable recovery move, and works for his 140 / 100 / 110 defenses, only furthered under a Sandstorm. Terrible offensive traits means Terreciel needs to use Seismc Toss or Night Shade to get by, which although aren't poor options but leave opening for the conflicting type.