Working on a good competitive team right now. Waiting until my Tyranitar can come in from the Pokemon Bank to start a pseudo-sand strat, as well as attempting to prepare another good team that isn't dependent on sun, but could benefit a good bit. The two megas I'm preparing for their respective teams:
Garchomp(PeytnManning)@Garchompite
Ability: Sand Veil
EVs: 252 Attack, 252 Speed, 4 HP
Adamant Nature
-Swords Dance
-Earthquake
-Stone Edge
-Outrage
Acting as the MVP of the team, MegaChomp is going to make an amazing partner with Sand-Stream Tyranitar once I get mine in. MegaChomp's ability pumps its attack up to insane levels in the sand. Stone Edge is there just so it's not a sitting Togekiss duck, with Outrage and Earthquake being the dual-stab combo. Swords Dance can be used on a free turn to make MegaChomp into your worst nightmare if the sand is still up.
Charizard@CharizarditeY
Ability: Blaze
EVs: 252 Special Attack, 252 Speed, 4 HP
Modest Nature
-Solar Beam
-Air Slash
-Fire Blast
-Roost/Focus Blast
I do have a MegaZardX that I love, but this one will be the crux of a different team I'm building. Drought makes Zard's Fire Blast insanely powerful, and give Solar Beam a 0 charge time. I'm thinking of maybe pairing a Ninetails with this, to keep the Drought momentum going, but we'll see. I can't decided if I should opt for Roost for dependable recovery, or go for Focus Blast to round out the coverage well.