To be blunt with you, Solrock is mediocre because while it has Levitate to negate one of its weaknesses, it still has 6 other weaknesses to deal with. While Tyranitar has more weaknesses, its greater bulk and offensive presence is what gives it the nod ahead:
-Stealth Rock
-Crunch/Pursuit
-Rock Slide/Ice Beam/Thunder Wave
-Fire Blast
Nature: Sassy
EVs: 248 HP/136 Def/124 SDef
Item: Leftovers/Smooth Rock
Ability: Sand Stream
While Water Pulse does give Togekiss more hax to abuse, it's just not worth it, since it can get by with just paralysis and flinching:
-Thunder Wave
-Air Slash
-Aura Sphere/Dazzling Gleam/Heal Bell/Defog
-Roost
Nature: Bold/Calm
EVs: 248 HP/252 Def/8 SDef (Bold) or 248 HP/8 Def/252 SDef (Calm)
Item: Leftovers
Ability: Serene Grace
While it's true that Slurpuff can use Belly Drum + Unburden, it needs tons of support to do so; you need to get rid of any counters to it before you send it out. If Slurpuff is forced out in some way, you lose the Unburden boost, meaning that you only have one chance to sweep with it. You're also making it do too much at once; why are you making it do offensive and defensive roles at once? Sylveon is a better Wish passer because of its higher HP:
-Wish
-Protect
-Hyper Voice
-Heal Bell
Nature: Bold
EVs: 252 HP/220 Def/36 SDef
Item: Leftovers
Ability: Pixilate
Dual Screening is better left to hyper-offensive teams to compensate for the team's general frailty. So Klefki isn't of much use here. This team appears to be stall-based, IMO, so stuff like Ferrothorn, Jirachi or Bronzong can be used in Klefki's place:
Ferrothorn:
-Stealth Rock/Spikes
-Leech Seed
-Power Whip/Protect
-Gyro Ball/Thunder Wave
Nature: Relaxed
EVs: 252 HP/88 Def/168 SDef
Item: Leftovers
Ability: Iron Barbs
Jirachi:
-Stealth Rock
-Iron Head
-U-turn
-Body Slam/Fire Punch
Nature: Careful
EVs: 252 HP/176 SDef/80 Spe
Item: Leftovers
Bronzong:
-Stealth Rock
-Gyro Ball
-Earthquake
-Hidden Power (Ice)/Protect/Toxic
Nature: Sassy
EVs: 252 HP/4 SDef/252 Spe
Item: Leftovers
Ability: Levitate
Sylveon does whatever Umbreon can do better. Foul Play works off the target's attacking stat, not the user's; it even ignores your own Attack boosts from Curse. Instead, I'd replace Umbreon with something that synergizes with Sableye and the Steel of choice, Tentacruel. Tentacruel also disposes of Fairies for Sableye and covers the Fire weakness of the Steel:
-Scald
-Acid Spray
-Sludge Bomb/Knock Off
-Rapid Spin
Nature: Calm
EVs: 240 HP/252 SDef/16 Spe
Item: Black Sludge
Ability: Liquid Ooze
You might as well run max HP/max Defense on Mega Sableye, tbh, as its Special Defense will already be taken care of by Calm Mind.