What would one thing would you change on your favourite champion to make them very strong?
You may only change one number for a certain champion and may only be doubled or halved. You can not change an ability or add something to it. Need something creative to come up with. Try to find the strongest single change.
For example:
her ult can now stack up to 6.
Another example:
her ult range is doubled.
Who is the strongest with one quick change?
Note: Akali isn't my favourite, just something that popped into my head :D
My fav:
's Q now scales twice as much on all levels
or
Passive: Kills give 50 100 gold for a kill with an additional 2 4 gold per stack
The AP ratio on her E is doubled. Bwahahahaha!
The AD ratio on her W is doubled. So much mixed damage!
passive: Number of marks needed to stun target changed to 2. Down from 4.
Q root now lasts twice as long
Total ultimate damage is now doubled (yes, I now gain more damage from your own AP than you do).
Bubble impact time halved / Bubble Size doubled
passive gives him more armor and MR to compensate for manaless champs, oh wait, there you go, make him manaless with higher cooldown reduction :D
Double duration on her stun. Better nerf Irelia heheh such an evil change.
w procs every auto attack and longer stuns.
Q now is global or 
Q is now global
R's cooldown is now six seconds at all ranks.
Xin's ulti now deals 30% of max health, not current health.
: The number of soldiers he can make is equal to his level. W costs no mana.
: Ultimate cooldown is 10 seconds. Ultimate lasts 10 seconds.
: Gains armor equal to the amount of armor he looks like he should have.
...I have more
Make her E magic damage again!!!
Her ult also makes her take reduced damage from selected victim
His cleavers can go through you.
invulernerability time doubled, get rekt
Ult range is doubled.
his w deals 20% opponents max hp and scales 50%ap ATLEAST
he is getting remade, so just make his bombs 120% ap since they are skill shots and his only dmg source
Ulti armor pen is doubled, 100% bonus armor pen XDDD
Her Ult now makes her invulnerable for the duration of the attack itself.
Double range on his ult,
Remove the nerf of xerath in 4.2
The AoE in his ultimates charges are doubled
i dont think i can help him with 1 change or 10..........or 1000000..........is there any human number that would be close to the number of buffs we have to give him?
Higher ult stack limit
Starts with 1 evolution point
Her mana costs on her q and e are reduced
can now walk around and use shunpo during her ult
: Double the duration of her stun or double the slow from her Q active.
The AP ratios on Spirit Fire are doubled (120% for the initial hit, 24% per second). AP Tank Nasus is now meta.