Nice team I have some suggestions and sorry if my suggestions are under par to what they may have used to be but I'm just getting back into Ou.
Anyway the team looks good but a few changes need to be made.
Genesect
Couldn't be more perfect
Breloom
Not so perfect
You have made a hybrid between a Technicion abuser and Posion heal set.
If you want a Poison Heal set use this
Breloom (M) @Toxic Orb
Trait: Poison Heal
EVs: 236 HP / 212 SpD / 60 Spe
Carefull Nature
-Bulk Up
-Spore
-Seed Bomb
-Drain Punch
This is standard set but I much prefer a Technician set, it hits very hard though comes at a cost of less bulk.
Breloom (M) @Leftovers
Trait: Technicion
EVs: 4 HP / 252 Atk / 252 Spe
Adamant Nature
-Swords Dance
-Bullet Seed
-Spore
-Mach Punch
One of the two really your set isn't currently working as you have no technician boost on your moves making them inferior to moves such as Seed Bomb.
Alakazam
OK two problems I see here.
1. Syncronise? Defintly go Magic Guard, without it maybe Alakazam would be Uu.
2. It doesn't have the bulk to set up with Cm so try using Hidden Power Fire to make up for lack of fire coverage.
Dragonite
I'm certainly not keen on this set as it out speeds nothing almost if you run 252 Speed you have a chance of not being KO'd by Modest HP Ice Heatran.
Also I see where the set is going and without Dragon Dance it isn't going far maybe use standard set.
Cloyster
You seem to have misplaced Shell Smash
Swap Ice Shard as you have some priority in the team already and Icicle Crash does a better Job.
Also swap Hydro Pump for more reliable Razor Shell.
Landorus-T
Ive never used this guy but from our moveset page and my small knolage on the Pokemon I suggest running 252 Speed and Jolly, otherwise you are going to get beat by Pokemon that usually you should out speed.
Also maybe try Out Scarf with Adamant.
Overall your team looks decent though you have a small ice problem and mamo Problem so I suggest swapping Landorus to Terrakion.
Same Movepool and similar set.
Terrakion @Choice Scarf
Trait: Justified
EVs: 252 Atk / 4 Def / 252 Spe
Adamant/Jolly Nature
-Close Combat
-Stone Edge
-Earthquake
-X-Scissor
This Pokemon serves the same role and hits hard as well, He also counters Scarfed mamo.
