[Champion Concept] Migalia, The Runecrafting Demon (4 forms champ)
Attack range: 180
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Passive: Rune-forms: you transform into another form when you craft 2 runes. Your transformation depends on runes crafted. Transforming into any form reset cooldown of your Q, W and E abilities (except normal form).
Witch Form (2 pink runes or 1 pink and 1 purple rune) Your basic attacks hex your target dealing additional 20/40/60 (+10% of ability power) magic damage over 6 sec stacking up to 3 times. In addition, your attack range will be increased by 400.
Banshee Form (2 purple runes or 1 purple and 1 black rune) Your basic attack hits every enemy around your main target and heal you for 1/2/3/4/5/6% of damage done.
Monster Form (2 black runes or 1 black and 1 pink rune) Your basic attacks increase your attack speed by 5/7/10% for 3 sec stacking up to 4 times.
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Normal Form: Death Slash [q] Your next basic attack deals 50/70/90/110/130 (+35% of ability power) magic damage and generates 1 purple rune. Cooldown: 8 sec Mana cost: 30
Witch Form: Death Hex [q] Curse your target to suffer 90/130/170/210/250 (+50% of ability power) magic damage over 5 sec. Cooldown: 10 sec Mana cost: 45 Range: 600
Banshee Form: Death Veil [q] Cause 50/80/110/140/170 (+35% of ability power) magic damage to all enemies around you and heal you for 15% of damage done. Cooldown: 10 sec Mana cost: 50 Range: 360
Monster Form: Death Smash [q] Cause your next basic attack to do 30/50/70/90/110 (+25% of ability power) bonus physical damage and knock nearby enemies up into air for 0,5 sec. Cooldown: 13/12/11/10/9 sec Range: 200
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Normal Form: Demon's Step [w] Jump to targeted area dealing 40/60/80/100/120 (+30% of ability power) magic damage to enemies inside it. Generates 1 pink rune. Cooldown: 12 sec Mana cost: 40 Range: 460 Range of AOE: 120
Witch Form: Witch's Night [w] Become invisible for 1/ 1,5/ 2/ 2,5/ 3 sec. Cooldown: 14 sec Mana cost: 30
Banshee Form: Spirit Travel [w] For next 3/ 3,25/ 3,5/ 3,75/ 4 sec you can pass through units, walls and structures. Cooldown: 18/17/16/15/14 sec Mana cost: 25
Monster Form: Monstrous Rush [w] Charge a distance dealing 70/105/140/175/210 (+40% of ability power) physical damage to all enemies in your patch. Cooldown: 12 sec Range: 485
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Normal Form: Rune Twister [e] Deal 60/90/120/150/180 (+45% of ability power) magic damage to all enemies around you and knock them away from you. Generates 1 dark rune. Cooldown: 10 sec Mana cot: 50 Range: 320 Knock back distance: 235
Witch Form: Dark Storm [e] Deal 30/40/50/60/70 (+20% of ability power) magic damage every sec for 3 sec to enemies in targeted area. Cooldown: 6 sec Mana cost: 70 Range: 750 Range of AOE: 185
Banchee form: Spook [e] Cause 50/85/120/155/190 (+35% of ability power) magic damage to all enemies in front of you in a cone and cause them to run in fear for 1,5 sec. Cooldown: 12 sec Mana cost: 55 Range: 500 Width: 450
Monster Form: Runeforged Skin [e] Increase your armor and magic resist by 10/13/16/19/22% for 4 sec. In addition, reduce chance you will be critically hit by 20% for duration of this ability. Cooldown: 10 sec
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Rune of Omnipower [r] (you start with this ability) Gain a beneficial buff based on your current form for 5 sec. When it ends you will return to your normal form and will not be able to craft any runes for 10 sec. You can use this ability only while transformed. Cooldown: 50 sec
Witch Form: gain 10/15/20/25 bonus magic penetration, 5/8/11/14% bonus spell vamp and 7/8/9/10% bonus ability power.
Banshee Form: gain 5/10/15/20% bonus cooldown reduction, 20/25/30/35% bonus movement speed and reduce all physical damage taken by 15/20/25/30%.
Monster form: gain 5/10/15/20 bonus armor penetration, 20/25/30/35 bonus armor and magic resist, and your basic attacks will slow movement speed of your target by 20/25/30/35% for 1,5 sec.
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Well, as you can see she have 4 forms and should be focused around 1 out of 3 forms. Possible builds could be:
For witch:
For banshee:
For monster:

and
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