Champion Design Challenge
Make a champion kit composed of any keystone rune or any item (old or new).
Onhit items will work like how Kled's W has a cooldown. Items that only have passives will function as active items. Try to adjust it all to a reasonable level.
Give your champion a name, and if possible, a theme. Here's my example, I'm calling it the Spirit Walker, an annoying mage support akin to brand
P
Restore mana equal to 15% of damage taken from champions. Restore health equal to 20% of mana spent, up to 25 health per cast, while toggle abilities can heal for up to 25 per second.
After using an ability, restore 8% of missing health and 3% of missing mana over 3 seconds.
Q
Deals 100-220 magic damage and steals 25% of the target's movement speed for .75 seconds (2 second cooldown).
W
Summons 2 ghosts for 6 seconds that seek out nearby enemy champions. Ghosts, on contact, reveal and slow enemy champion by 40% for 2 − 5 (based on distance traveled) seconds (30 second cooldown).
E
Your next ability applies a damage-over-time effect for 3 seconds that deals a total of 4.5% of target's maximum health bonus magic damage, with each tick of damage occurring every 0.5 seconds. This total damage is increased to 7.5% of target's maximum health against slowed or immobilized units, and capped at 100 damage per second against monsters. (12 second cooldown)
R
Deals 15% of the target champion's maximum health in magic damage and increases all subsequent magic damage taken by the target by 20% for 4 seconds (750 range) (90 second cooldown).
Here's an example of a build

I'm interested to see what people can come up with.