Red Robin? You're the food.
Yveltal @ Life Orb
Trait: Dark Aura
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Dark Pulse
- Oblivion Wing
- Roost
- Focus Blast
One thing I like about Yveltal is its neutral coverage. Between Dark and Flying STAB and Fighting as a coverage against Rocks, Ice, and Steel, this set can hit anything hard. I'm not sure if Dark Aura adds to Dark STAB, but either way Dark Pulse hits anything that doesn't resist hard. Oblivion Wing, with its amazing recovery effect, mitigates the damage from LO and potential hazards. Focus Blast rounds out his coverage, hitting Tyranitar for massive damge. Roost is not the best move, but can be used to have extra life. Substitute could replace it, helping Yveltal to have staying power, while soaking up Fairy or Electric moves for him. If you really want, U-Turn can be an option, but it is far better on Specs/Scarf sets.
This is just to show what Yveltal can go up against as examples.
Mewtwo matchup: This set is surprisingly effective on the average "Psychokiller" Mewtwo. For starters, while Mewtwo's faster Ice Beam does only 57.3-68% (Still a lot though, factoring Yveltal's LO recoil), Yveltal can counter with Dark Aura Dark Pulse for a guaranteed OHKO, which is why I prefer Roost in that regard, as he can heal after.
Tyranitar matchup: Normally for most Flying types, Tyrantitar would either be their bane or, if they have Fighting moves or a sub-type that resists its STAB, set up bait or even a clean kill. Yveltal falls under the ladder category, with access to Focus Miss, making the Tyrant his bitch. Provided if the inaccurate ball of pure energy manages to hit the lumbering pile of rocks, its gonna be a clean kill (unless if its Assault Vested) to a Bulky Offensive T-Tar. However, should they be running SpD Tyranitar, it will be only a 2HKO (Again if it hits)