http://www.smogon.com/dp/pokemon/celebi
I've been testing a newer defensive Celebi lead that has been incredible and incredibly frustrating for my opponents. It's a bit of a mix between Uber Lead Celebi and OU Lead Celebi, so it might be OO or absorbed into one of those two sets if not outright scrapped for a lack of effectiveness or uniqueness (which, imo, is not the case). I've never done one of these before, so any help will be appreciated.
[SET]
name: Utility Lead
move 1: Stealth Rock
move 2: Thunder Wave
move 3: Leaf Storm
move 4: U-turn / Protect
item: Occa Berry
nature: Calm
evs: 252 HP / 100 Def / 60 SpA / 96 SpD
[SET COMMENTS]
<p>A bulkier take on Lead Celebi, this set is designed to set up Stealth Rock and weather hits while performing a valuable scouting function with the Thunder Wave / U-turn combination. It matches up well against OU's most common leads, all but guaranteeing Stealth Rock while 2HKOing faster Taunt users like Azelf and Aerodactyl. Due to Celebi's impressive defenses, Thunder Wave is usually the best opening move, as it will give Celebi's switch-in a much easier time building momentum and will allow it to set up Stealth Rock on the following turn or U-turn out to an appropriate counter, saving Stealth Rock for later on in the match.</p>
<p>Thanks to Occa Berry and the given EVs, there is no common lead that can OHKO Celebi without a critical hit, allowing ample time to paralyze the opponent, set up Stealth Rock, and/or U-turn out, in whatever order seems best. In fact, the only common moves in OU that can OHKO this Celebi without stating-up first (bar Explosion and Selfdestruct) are Choice Band Scizor's U-turn and Choice Band Tyranitar's Pursuit on the switch. Celebi can U-turn out of Scizor with little worry, making Tyranitar the biggest threat to this set; however, if Celebi stays in and has above 57% HP, it is guaranteed two turns to either 2HKO with Leaf Storm + Stealth Rock damage 89% of the time, or both paralyze Tyranitar and hit it for 56.7% - 66.7% damage before going down, turning Tyranitar into much less of a threat for later on in the battle. On the less common side of things, Heracross's Megahorn, Choice Specs Magnezone's Signal Beam, and Adamant Choice Band Flygon's / Infernape's U-turn will OHKO, while Choice Specs Jolteon's Signal Beam has a 33% chance to OHKO, so be on the lookout for them.</p>
<p>The EVs are tailored to the lead metagame, such that Celebi is never 2HKOed by Metagross's Meteor Mash or Azelf's Fire Blast (barring max damage both turns for Azelf), meaning Celebi can paralyze, set up Stealth Rock, and U-turn to the appropriate counter, breaking opposing Focus Sashes in the process. They give Celebi 404 / 261 / 286 defenses, which is bulky enough to take +1 or +2 hits from the likes of Dragon Dance Gyarados and Calm Mind Latias mid to late-game while halting their sweeps with Thunder Wave. 60 Special Attack EVs are the minimum required to 2HKO opposing Aerodactyl and Azelf while OHKOing Swampert and having a 33% chance to OHKO Hippowdon.</p>
<p>Protect may be used over U-turn in the fourth slot if you want Celebi to scout for Choice users or Explosion, which is especially useful for a lead like Celebi, as many paralyzed leads such as Metagross, Heatran, and Azelf will prefer to go out with a bang over staying in as death fodder for later. Celebi is also great at drawing in Choice users, especially Scizor, who love to abuse U-turn to hit Celebi's glaring 4x weakness, so Protect may be useful in those cases so you can switch in something to take the hit and save Celebi for later. Usually, however, U-turn will be more useful for breaking Sashes and advantageously switching in other teammates, so Protect is the lesser option.</p>
<p>This Celebi has problems staying in for more than a few turns and poses no offensive threat to the likes of Infernape, Heatran, or Metagross, and its only powerful attack drastically lowers its Special Attack stat every time it uses it. As such, teammates that can quickly come in and take advantage of a paralyzed foe make great partners. Life Orb or Substitute Heatran is Celebi's classic partner and can grab a Flash Fire boost from the likes of leading Infernape, Heatran, and Azelf who take the offensive route right off the bat, although it must be wary of ShucaTran. Bulky stat-uppers like Gyarados and Latias also enjoy the immediate threat they pose against paralyzed foes, as does Substitute +3 Attacks Machamp. The only common leads Celebi has trouble with are Gliscor and sleep-inducing leads like Roserade and Smeargle. Gliscor, who can Taunt Celebi and has access to Roost, prevents Celebi both from 2HKOing and getting Stealth Rock up. Roserade and Smeargle both outrun and can use Sleep Powder/Spore to set up entry hazards, although Natural Cure will allow Celebi to switch out and free itself of status. For these reasons, Starmie makes an excellent partner, as it can scare off Gliscor, put a dent in Roserade and Smeargle, and has the added bonus of using Rapid Spin to remove opponents' entry hazards. It also has Natural Cure to free itself of poison / sleep status, so it won't be crippled throughout the match (it is advisable, however, to not switch Starmie directly into Roserade unless its Focus Sash is broken, as its STAB Grass attacks will OHKO).</p>
I've been testing a newer defensive Celebi lead that has been incredible and incredibly frustrating for my opponents. It's a bit of a mix between Uber Lead Celebi and OU Lead Celebi, so it might be OO or absorbed into one of those two sets if not outright scrapped for a lack of effectiveness or uniqueness (which, imo, is not the case). I've never done one of these before, so any help will be appreciated.

[SET]
name: Utility Lead
move 1: Stealth Rock
move 2: Thunder Wave
move 3: Leaf Storm
move 4: U-turn / Protect
item: Occa Berry
nature: Calm
evs: 252 HP / 100 Def / 60 SpA / 96 SpD
[SET COMMENTS]
<p>A bulkier take on Lead Celebi, this set is designed to set up Stealth Rock and weather hits while performing a valuable scouting function with the Thunder Wave / U-turn combination. It matches up well against OU's most common leads, all but guaranteeing Stealth Rock while 2HKOing faster Taunt users like Azelf and Aerodactyl. Due to Celebi's impressive defenses, Thunder Wave is usually the best opening move, as it will give Celebi's switch-in a much easier time building momentum and will allow it to set up Stealth Rock on the following turn or U-turn out to an appropriate counter, saving Stealth Rock for later on in the match.</p>
<p>Thanks to Occa Berry and the given EVs, there is no common lead that can OHKO Celebi without a critical hit, allowing ample time to paralyze the opponent, set up Stealth Rock, and/or U-turn out, in whatever order seems best. In fact, the only common moves in OU that can OHKO this Celebi without stating-up first (bar Explosion and Selfdestruct) are Choice Band Scizor's U-turn and Choice Band Tyranitar's Pursuit on the switch. Celebi can U-turn out of Scizor with little worry, making Tyranitar the biggest threat to this set; however, if Celebi stays in and has above 57% HP, it is guaranteed two turns to either 2HKO with Leaf Storm + Stealth Rock damage 89% of the time, or both paralyze Tyranitar and hit it for 56.7% - 66.7% damage before going down, turning Tyranitar into much less of a threat for later on in the battle. On the less common side of things, Heracross's Megahorn, Choice Specs Magnezone's Signal Beam, and Adamant Choice Band Flygon's / Infernape's U-turn will OHKO, while Choice Specs Jolteon's Signal Beam has a 33% chance to OHKO, so be on the lookout for them.</p>
<p>The EVs are tailored to the lead metagame, such that Celebi is never 2HKOed by Metagross's Meteor Mash or Azelf's Fire Blast (barring max damage both turns for Azelf), meaning Celebi can paralyze, set up Stealth Rock, and U-turn to the appropriate counter, breaking opposing Focus Sashes in the process. They give Celebi 404 / 261 / 286 defenses, which is bulky enough to take +1 or +2 hits from the likes of Dragon Dance Gyarados and Calm Mind Latias mid to late-game while halting their sweeps with Thunder Wave. 60 Special Attack EVs are the minimum required to 2HKO opposing Aerodactyl and Azelf while OHKOing Swampert and having a 33% chance to OHKO Hippowdon.</p>
<p>Protect may be used over U-turn in the fourth slot if you want Celebi to scout for Choice users or Explosion, which is especially useful for a lead like Celebi, as many paralyzed leads such as Metagross, Heatran, and Azelf will prefer to go out with a bang over staying in as death fodder for later. Celebi is also great at drawing in Choice users, especially Scizor, who love to abuse U-turn to hit Celebi's glaring 4x weakness, so Protect may be useful in those cases so you can switch in something to take the hit and save Celebi for later. Usually, however, U-turn will be more useful for breaking Sashes and advantageously switching in other teammates, so Protect is the lesser option.</p>
<p>This Celebi has problems staying in for more than a few turns and poses no offensive threat to the likes of Infernape, Heatran, or Metagross, and its only powerful attack drastically lowers its Special Attack stat every time it uses it. As such, teammates that can quickly come in and take advantage of a paralyzed foe make great partners. Life Orb or Substitute Heatran is Celebi's classic partner and can grab a Flash Fire boost from the likes of leading Infernape, Heatran, and Azelf who take the offensive route right off the bat, although it must be wary of ShucaTran. Bulky stat-uppers like Gyarados and Latias also enjoy the immediate threat they pose against paralyzed foes, as does Substitute +3 Attacks Machamp. The only common leads Celebi has trouble with are Gliscor and sleep-inducing leads like Roserade and Smeargle. Gliscor, who can Taunt Celebi and has access to Roost, prevents Celebi both from 2HKOing and getting Stealth Rock up. Roserade and Smeargle both outrun and can use Sleep Powder/Spore to set up entry hazards, although Natural Cure will allow Celebi to switch out and free itself of status. For these reasons, Starmie makes an excellent partner, as it can scare off Gliscor, put a dent in Roserade and Smeargle, and has the added bonus of using Rapid Spin to remove opponents' entry hazards. It also has Natural Cure to free itself of poison / sleep status, so it won't be crippled throughout the match (it is advisable, however, to not switch Starmie directly into Roserade unless its Focus Sash is broken, as its STAB Grass attacks will OHKO).</p>