Scarf Celebi
Once T tar is down, Scarf Celebi can spam leaf storm/ giga drain. If it runs hp ice you really won't be having fun. Actually, scarf celebi takes on half your team with leaf storm (rotom, terrakion, and keldeo) and if he predicts the switch in he can take on the other two with hp ice (landorus and mence). Even if Ttar is alive, he still does over 50% with rocks when using leaf storm, so no matter what if it is preserved your not having a fun day.
Celebi vs most of your team with leaf storm;
252SpAtk Celebi (Neutral) Leaf Storm in Sandstorm vs 252HP/252SpDef Leftovers Tyranitar (+SpDef): 46% - 53% (186 - 218 HP). Guaranteed 3HKO. 3% chance to 2HKO with Leftovers.
252SpAtk Celebi (Neutral) Leaf Storm in Sandstorm vs 4HP/0SpDef Leftovers Terrakion (Neutral): 85% - 101% (278 - 330 HP). Guaranteed 2HKO. 11% chance to OHKO.
252SpAtk Celebi (Neutral) Leaf Storm in Sandstorm vs 4HP/0SpDef Leftovers Keldeo (Neutral): 128% - 151% (416 - 492 HP). Guaranteed OHKO.
252SpAtk Celebi (Neutral) Leaf Storm in Sandstorm vs 248HP/232SpDef Leftovers Levitate Rotom (+SpDef): 89% - 104% (270 - 318 HP). Guaranteed 2HKO. 31% chance to OHKO.
252SpAtk Celebi (Neutral) Leaf Storm in Sandstorm vs 4HP/32SpDef Leftovers Landorus Therian (Neutral): 68% - 81% (220 - 261 HP). Guaranteed 2HKO.
Your response (I only did mons that will survive a hit and are not named t tar)
252Atk Choice Band Terrakion (Neutral) Quick Attack in Sandstorm vs 4HP/0Def Leftovers Celebi (Neutral): 19% - 22% (66 - 78 HP). Guaranteed 6HKO.
252Atk Choice Band Terrakion (Neutral) Close Combat in Sandstorm vs 4HP/0Def Leftovers Celebi (Neutral): 42% - 50% (146 - 172 HP). Guaranteed 3HKO.
252Atk Choice Band Terrakion (Neutral) Stone Edge in Sandstorm vs 4HP/0Def Leftovers Celebi (Neutral): 71% - 84% (244 - 288 HP). Guaranteed 2HKO.
28SpAtk Rotom (Neutral) Hydro Pump in Sandstorm vs 4HP/0SpDef Leftovers Celebi (Neutral): 20% - 23% (69 - 82 HP). Guaranteed 5HKO.
My analysis
So basically hazards and sandstorm will wear him down quickly as he will need to switch out after every leaf storm. my main point is this guy hurts, a lot. The best thing to do is put on x scissor onto terrakion or change possibly change terrakion to scizor or mamoswine or something. I didn't do calcs on salamence cuz I'm lazy and leaf storm won't hit hard but hp ice definitely will. Plus speed ties are shenanigans.
Sub Chomp
If Garchomp can get behind a sub he pretty much can take out any one of your mons right there or really hurt them. Fortunately you have little he can get a sub up against but the lack of a steel type isn't helping you is what I'm trying to say I guess
Chances for a sub
• Hydro Pump miss
• Whenever landorus is locked into stone edge
• Salamence locked into stone edge
•Terrakion locked into quick attack
• Various Miss predicts
Garchomp vs your team
252Atk Garchomp (Neutral) Outrage vs 4HP/0Def Keldeo (Neutral): 66% - 78% (214 - 253 HP). Guaranteed 2HKO.
252Atk Garchomp (Neutral) Outrage vs 4HP/32Def Landorus Therian (Neutral): 64% - 76% (207 - 244 HP). Guaranteed 2HKO.
252Atk Garchomp (Neutral) Outrage vs 4HP/252Def Levitate Rotom (Neutral): 61% - 72% (148 - 175 HP). Guaranteed 2HKO.
252Atk Garchomp (Neutral) Outrage vs 4HP/0Def Salamence (Neutral): 142% - 168% (474 - 558 HP). Guaranteed OHKO.
252Atk Garchomp (Neutral) Earthquake vs 4HP/0Def Terrakion (Neutral): 109% - 130% (356 - 422 HP). Guaranteed OHKO.
252Atk Garchomp (Neutral) Earthquake vs 252HP/0Def Tyranitar (Neutral): 74% - 88% (302 - 356 HP). Guaranteed 2HKO.
Your team hitting Garchomp
0Atk Unnerve Tyranitar (Neutral) Crunch vs 4HP/0Def Garchomp (Neutral): 32% - 38% (117 - 138 HP). Guaranteed 4HKO.
252Atk Choice Band Terrakion (Neutral) Close Combat vs 4HP/0Def Garchomp (Neutral): 85% - 100% (306 - 360 HP). Guaranteed 2HKO. 3% chance to OHKO.
252Atk Choice Band Terrakion (Neutral) Quick Attack vs 4HP/0Def Garchomp (Neutral): 18% - 22% (68 - 81 HP). Guaranteed 6HKO.
252Atk Salamence (Neutral) Outrage vs 4HP/0Def Garchomp (Neutral): 117% - 139% (422 - 498 HP). Guaranteed OHKO.
28SpAtk Rotom (Neutral) Hydro Pump vs 4HP/0SpDef Garchomp (Neutral): 44% - 52% (159 - 187 HP). Guaranteed 3HKO. 7% chance to 2HKO.
252Atk Landorus Therian (Neutral) Earthquake vs 4HP/0Def Garchomp (Neutral): 51% - 61% (186 - 219 HP). Guaranteed 2HKO.
252Atk Landorus Therian (Neutral) U-turn vs 4HP/0Def Garchomp (Neutral): 24% - 28% (87 - 103 HP). Guaranteed 5HKO.
252SpAtk Keldeo (Neutral) Secret Sword vs 4HP/0Def Garchomp (Neutral): 40% - 47% (144 - 171 HP). Guaranteed 3HKO.
252SpAtk Keldeo (Neutral) Hydro Pump vs 4HP/0SpDef Garchomp (Neutral): 62% - 73% (223 - 264 HP). Guaranteed 2HKO.
Analysis
With a sub he pretty much gets a free kill or seriously hurts anything. Landorus switching in for the intimidate is your best course of action but if you don't have landorus or landorus is already out, your in trouble. The best thing to do if lando is down is switch in something as he subs to break the sub next turn then send in something that can reliably kill it as it outrages. Silver had some good suggestions for what to do about this guy, I'm just trying to give you some ideas on what might threaten you in the right circumstances
Mix Ape
Mix ape could be a problem if it runs hp ice and wins a speed tie or two
*I got lazy, but he looks threatening with nearly unresisted close combat bar 2 mons*
Wait... Why am I giving you strategies on how to take them down? You'd good enough to figure it out mid battle...