Congratulations on winning RMT of the week! Even though Specially Defensive Hippowdon is a cute way of checking Sun, you're still weak to it. Things like Venusaur can bypass both Hippowdon and Zapdos after Stealth Rock. Opposing SubToxic Tentacruel and SubProtect Gliscor also make your life miserable as well since the former beats your Jellicent and can burn Hippowdon while the latter can PP Stall Gyro Ball from your Forretress and then proceed to sweep you. Kyurem-B and regular Kyurem are both problematic since your team is relatively slow and Scarf Jirachi is rather easy to set up on if you don't hax. You mentioned both Keldeo and Tyranitar in tandem being threatening as well. To fix these weaknesses, trying out a Latias instead of Zapdos could work. SubCM Latias can set-up on Toxic-mons like Gliscor, a Pokemon who is walled by Latias, and SubToxic Tentacruel if you don't suck and switch into the obvious Toxic. The standard spread of 248 HP / 8 SDef / 252 Spe @ Leftovers with a Timid Nature and moves of Substitute / Calm Mind / Roost / Dragon Pulse should work well for you. Latias checks Venusaur, gives you a secondary check to Keldeo that isn't easily trappable by Pursuit due to Substitute, and gives you a win condition in a sweeper which the team current lacks. I always like having some offensive pressure in my stall teams. Additionally, Latias is a much more durable Landorus check because it isn't weak to Stealth Rock and can outspeed both Kyurem formes unless they are Scarfed. With this change, Scizor becomes much more threatening. Simply putting Jellicent's SpD EV's into Def and using a Bold Nature should give you a solid Scizor counter. I wish you the best of luck.