Here are some Items that just?.came to me in a dream o.o

Shadow Sneakers:
Unique Passive: Movement Speed 2
Unique Passive: when Stealthed you can move through units and the effect of the boots are increased to Movement Speed Three.
Builds From: Boots of Speed
Total cost: 1100

Echo of Life
Unique Aura: Restores 10 Mana p5 and 10 Health p5 to yourself and nearby friendly champions
Unique Active: Restore Health and Mana to yourself and all nearby champions at a rate of 10 * Champion Level. 2 minute Cooldown

Builds From: Mana Manipulator and Rejuvenation Band
Total cost: 1300

Tome of Respite
+25 AP 10 Hp5
Builds from: Amplifying Tome and Rejuvenation Band
Total cost: 1000

Book of Unending
+35 Ap 15 hp5 10% Cooldown Reduction +250 Health
Builds from: Kindlegem and Tome of Respite
Total Cost: 2200



Snake Bite:
40 percent attack speed bonus 20% Critical Strike Chance 20% Life Steal
Unique Passive: Your Attacks poison the Target, dealing Damage up to half your Champion Level per second for 8 seconds. This Poison can stack up to 5 Times.
Unique Passive: 10% Cooldown Reduction
Unique ACTIVE: Inflicts Target Enemy Champion with Grievous Wounds, causing 50% reduced healing and regeneration for 8 seconds. 30 second cooldown.

total cost: 3150



discuss

Problem 1: Unique Passives don't scale on champion levels (at least not yet, otherwise that Echo of Life item sounds fantastic).
Problem 2: There are not even 10 champions who use Stealth (don't count Leblanc, that 0.5 second stealth is literally to confuse people)
Problem 3: Snake Bite's build path? Is it Executioner's Calling and Recurve Bow? Well except for the combined scaling AND stackability, it's pretty cool.

I do like the ideas.