Rules: One person names a champion, and the person under them gives them a new, completely useless passive. Then they name their own champion and so on. Easy as that. Lets see how long this can go.
I'll start. 
Also, this should be played in chronological view.
Stoned Money: Wukong's armor and magic resistance are increased by 4 / 6 / 8 for each invisible nearby enemy champion
Respect for the Weak: Zed's basic attacks against targets below 50% health do no extra damage, because that would just be mean.
Up next: 
Deceit: Increases cooldowns by 15 seconds for every kill or assist
Persuasion of Force: Akali thinks her auto attacks deal bonus magic damage. Too bad it does nothing. Persuasion of Might: Akali thinks she gains spell vamp. Who would give such a broken passive to her. Her damages recoils and deals some of the damage done to herself.
Karma: If Teemo stands still and takes no action for 0.5 seconds, he becomes stealthed. Taking any action or being moved will break his camouflage and blind him for a few seconds.
Up Next: 
azir can summon turrets but they die within a minute and grant the enemy team turret kill gold
Passing wind: Every third auto attack causes yasuo to fart.
Next: 
Giant Enemy Crabgot: Due to being so massive, urgot has the burden of -50% movement speed
Up Next: 
Ruby, Emerald and Sapphire
Taric's shield prevents him from casting a spell until he autoattacks a unit. That auto attack will do less damage based on Taric's total armor, and will silence Taric for 2 seconds.
Next:
Vel'Koz abilities apply stacks, at three stacks the target gains vision of vel'Koz.
Next: 
ashe next crit strike heals enemy
next 
Irelia can no longer gain tenacity from items.
Next:
Tryndamere no longer gains bonus fury from critical strikes.
Next 
Karthus becomes a statue for 7 seconds after dying, delaying his respawn time by 7 seconds. This however does nothing but just look cool. No vision or skills. Just a statue.
1S Dice: Last hits earn 3 less gold than other champions.
Next: 
Yi gets confused, every 4th attack he hits himself
Unsustainable: Veigar's mana regeneration is decreased by 1% for each 1% of his maximum mana. What Burst?: Veigar thinks he gains permanent bonus ability power when he kills a champion from any source of damage. In fact, it permanently reduces his MR and Armor by 10% of current amount per kill/assist.
Up Next: 
Viktor's passive item is changed so that it grants 10 AP at level 18 and 100 bonus AP for every point thereafter that he levels up.
Diana's every 3rd attack will give short movement speed buff to enemy units that got hit by moon shape.
If Darius deals damage to enemy with his abilities or auto attacks, enemy will gain 5% cdr for 5 seconds up to 5 times for absolute no reason at all.
Everytime Lee use's an ability, he will miss every auto attack until the buff wears off
Next:
Miss Fortune loses 25 movement speed after not taking damage for 5 seconds, which gradually decreases to 70 movement speed over 5 seconds.
Next: 
Acid reflex: After Kog Maw uses his fourth ability in a row, he barfs onto himself, dealing half his ad to himself.
Next:
Extinguisher: Brand cannot use abilities in the river as water puts out fire. He also deals no damage to Nami, Fizz, Atlantean Syndra and all other water-themed champs.
Infected Needle
If Mundo has not cast an ability within the last 4 seconds, his health regen is reduced to 1 hp per second. When Mundo casts an ability, the cooldown of the rest of his abilities are increased by 2 seconds.
Next: 
Alone the Whole Time:
Diana's abilities apply "moonlight" to any enemy struck. This makes them glow softly. It does not grant vision as trying to see anything by moonlight alone is rather difficult.
Leashed Power: Whenever Syndra gains a max rank in a skill, the skill becomes more restrictive. Q: Deals less damage to champions. W: Slow becomes a speed zone for enemy champions. E: Cone becomes a line, only able to hit balls in a straight line. R: Maximum ball limit capped at the three surrounding Syndra.
When using an ability, Zac releases a blob. Stepping on a blob kills you, because Zac defends the weak, he doesn't kill them!
NEXT: 
Mundo loses 3% health every 5 seconds
NEXT: 
Cooldown is multiplied 2x everytime karma is damaged by enemy champion
NEXT:
Ball of Fur: Nidalee has to stop every 5 minutes for 10 seconds to get rid of the fur she has been licking off herself.
Next:
Cooldown is multiplied 2x everytime karma is damaged by enemy champion
NEXT:
Passive, Fish out of Water: Nami can only leave water for 10 seconds before she gets damaged (300 hp /second)
NEXT:
Clumsy: Whenever Teemo stands still for more than 1.5 seconds, he becomes visible to all enemies and takes 100% increased damage. Slowpoke: Leveling up Move Quick wears Teemo out, he is 50% slower when Move Quick isn't active
Up next:
EDIT: I hate typing a response and then realizing somebody posted the same thing while you were typing.
