So, it's basically another kind of Ability Power, dedicated to supports & utility mages.

But why?

After some thoughts and analyzes performed on champions in League, mostly full-utility as JannaSquare Janna, I realized that they have no true way of building. I mean, they do not have any attribute they would scale off. As offensive classes scale off offensive stats, defensive classes scale off defensive stats, what is left for utility classes? They have to increase attributes they don't use that well as other classes. Also, this makes them always no threat at all. And what, if we could make a choice, if we want to play any class offensive, defensive or utilitary (not sure if such a word exist)? Right now, if you'll build full AP on exemplary JannaSquare Janna, you still are not a threat for enemies. Plus, my personal opinion, but my eyes bleed as I see supports/wizards building as tanks. Someone will say, that that's the point and she should not be threat at all, as she is a support I, however will disagree, as she, being a mage, should also have choice of building offensively. But by just increasing her AP scalings, it could make her eventually too strong, considering she is in the right place in terms of balance. And that's why I would like to introduce you:

Spirit

This would restrict classic Ability Power to increase offensive attributes of spells (damage, damage buffs), while the Spirit would increase defensive attributes of spells (shields, heals, defense/utility buffs/debuffs) and eventually duration of effects caused. Not by large amount to prevent Dark Binding Dark Binding last 5 seconds. Adding Spirit to the game would naturally require lots of work, including changing scaling of most champions and total changes in some other, mostly supports. But wouldn't it bring lots of possibilities, as more LuluSquare Lulus, JannaSquare Jannas or NamiSquare Namis as wizards on other lanes, like BrandSquare Brand started to support?

Exemplary changes

General

  • New attribute Spirit has ben added to the game
    • Spirit is a form of defensive Ability Power, which enhances power of defensive/utilitary attributes of abilities cast.
    • 1 Spirit is worth ~62 gold.

Champions

SorakaSquare Soraka

  • Starcall Starcall
    • Power scaling increased from (+ 35% AP) to (+ 70% AP).
  • Astral Infusion Astral Infusion
    • Power scaling removed.
    • Added (+ 330% SPI) scaling.
  • Wish Wish
    • Power scaling removed.
    • Added (+ 315% SPI) scaling.

NamiSquare Nami

  • Aqua Prison Aqua Prison
    • Power scaling increased from (+ 50% AP) to (+ 70% AP).
  • Ebb and Flow Ebb and Flow
    • Healing power scaling removed.
    • Healing (+140% SPI) scaling added.
  • Tidecaller's Blessing Tidecaller's Blessing
    • Damage power scaling increased from (+ 20% AP) to (+ 25% AP).
    • Slow power scaling removed.
    • Added (+30% SPI) slow scaling.
  • Tidal Wave Tidal Wave
    • Increased power scaling from (+ 60% AP) to (+ 70% AP).

TaricSquare Taric

ZileanSquare Zilean

  • Chronoshift Chronoshift
    • Power scaling removed.
    • Added (+ 1300% SPI) scaling.

SonaSquare Sona

  • Hymn of Valor Hymn of Valor
    • Power scaling increased from (+ 50% AP) to (+ 65% AP).
  • Aria of Perseverance Aria of Perseverance
    • Power scaling removed from shield, healing and damage reduction.
    • Added (+ 125% SPI) scaling for healing.
    • Added (+ 170% SPI) scaling for shield.
    • Added (+ 20% SPI) damage reduction scaling from Power Chord.
  • Song of Celerity Song of Celerity
    • Power scaling removed from both haste and slow.
    • Added (+ 30% SPI) scaling to haste and (+ 20% SPI) scaling to slow.
  • Crescendo Crescendo
    • Power scaling increased from (+ 50% AP) to (+ 70% AP).

BardSquare Bard

KarmaSquare Karma

  • Inner Flame Inner Flame
    • Power scaling for increased from (+ 60% AP) to (+ 75% AP).
    • Power scaling for Soulflare Soulflare's detonation increased from (+ 60% AP) to (+ 75% AP).
  • Inspire Inspire
    • Power scaling removed.
    • Added (+ 230% SPI) scaling to shield and (10% SPI) scaling to haste.
    • Power scaling for Defiance Defiance changed from (+ 60% AP) to (+ 170% SPI).
  • Mantra Mantra
    • Now passively increases AP by 5% / 20% / 35% / 50% Spirit.

JannaSquare Janna

  • Howling Gale Howling Gale
    • Power scaling of minimum damage increased from (+ 35% AP) to (+ 40% AP).
    • Power scaling of bonus damage per second increased from (+ 10% AP) to (+ 20% AP).
  • Zephyr Zephyr
    • Power scaling of damage increased from (+ 50% AP) to (+ 75% AP).
    • Scaling of passive haste changed from (+ 2% AP) to (+ 10% SPI).
    • Scaling of slow changed from (+ 6% AP) to (+ 30% SPI).
  • Eye of the Storm Eye of the Storm
    • Scaling of shield changed from (+ 70% AP) to (+ 390% SPI).
    • Scaling of bonus AD increased from (+ 10% AP) to (+ 15% AP).
  • Monsoon Monsoon
    • Scaling changed from (+ 50% AP) to (+ 230% SPI).

LuluSquare Lulu

  • Glitterlance Glitterlance
    • Power scaling increased from (+ 50% AP) to (+ 60% AP).
  • Whimsy Whimsy
    • Power scaling for movement speed boost changed from (+ 5% AP) to (+ 20% SPI).
  • Help, Pix! Help, Pix!
    • Scaling of shield changed from (+ 60% AP) to (+ 315% SPI).
    • Scaling of damage increased from (+ 40% AP) to (+ 65% AP).
  • Wild Growth Wild Growth
    • Power scaling changed from (+ 50% AP) to (+ 325% SPI).

IvernSquare Ivern

  • Rootcaller Rootcaller
    • Power scaling increased from (+ 70% AP) to (+ 90% AP).
  • Triggerseed Triggerseed
    • Scaling of shield changed from (+ 80% AP) to (+ 370% SPI).
    • Damage scaling increased from (+ 70% AP) to (+ 90% AP).

LuxSquare Lux

MorganaSquare Morgana

  • Dark Binding Dark Binding
    • Scaling reduced from (+ 90% AP) to (+ 80% AP).
  • Black Shield Black Shield
    • Scaling changed from (+ 70% AP) to (+ 500% SPI).

OriannaSquare Orianna

  • Command Protect Command: Protect
    • Shield scaling changed from (+ 40% AP) to (+ 200% SPI).
    • Damage changed from 75% of shield to 60/105/150/195/240 (+ 45% AP).

Items

Forbidden Idol item Forbidden Idol

  • Unique passive removed.
  • Now grants 6 Spirit.

Ardent Censer item Ardent Censer

  • AP Granted reduced from 60 to 40.
  • Now grants 12 Spirit.
  • Cost increased from 650 to 850 (total cost increased from 2300 to 2500).

Mikael's Crucible item Mikael's Crucible

  • Unique passive removed.
  • Now grants 15 Spirit.
  • Cost increased from 500 to 800 (total cost increased from 2100 to 2400).

Redemption item Redemption

  • Removed unique passive increasing shielding and health.
  • Now grants 7 Spirit.
  • Cost increased from 650 to 850 (total cost increased from 2100 to 2300).

Talisman of Ascension item Talisman of Ascension

  • Recipe changed from Nomad's Medallion item Nomad's Medallion + Raptor Cloak item Raptor Cloak + 350 gold to Nomad's Medallion item Nomad's Medallion + Forbidden Idol item Forbidden Idol + 750 gold.
  • No longer grants armor.
  • Granted base health regeneration decreased from 150% to 25%.
  • Granted base mana regeneration increased from 75% to 125%.
  • Cooldown reduction increased from 10% to 20%.
  • Removed unique - point runner.
  • Now grants 15 Spirit.

Blackfire Torch item Blackfire Torch - Remade

  • Now built from: Forbidden Idol item Forbidden Idol + Fiendish Codex item Fiendish Codex + 700 gold (total 2400 gold).
  • + 50% Base mana regen
  • + 45 AP
  • + 10% Cooldown reduction
  • + 11 Spirit
  • Unique active - Strikes target enemy with Blackfire, dealing 10% of target's current health magic damage, decreasing damage it deals for 3 seconds by 15% and healing taken by 35%. 60 seconds cooldown; 700 range.

Force of Nature item Force of Nature - Remade

  • Now built from: Forbidden Idol item Forbidden Idol + Catalyst of Aeons item Catalyst of Aeons + 400 gold (total 2300 gold).
  • + 225 Health
  • + 300 Mana
  • + 50% Base mana regen
  • + 10% Cooldown reduction
  • + 11 Spi
  • Unique passive - Eternity
  • Unique passive - 12% of health you restore (in any way) is also restored to all other allied champions within 800 units.

Summary

I know I probably did many unnecessary things here, but it all was just to show you my idea in examples. The point is to make possible choice between offensive mage and defensive mage. Also, since there would be not enough items granting Spirit, I've added two new ones, one for offense, one for defense. They are the least important there, as this is about Spirit itself. Write down, what do you think!