Why Tank Fiora is so powerful
Lets consider what a full build tank Fiora at level 18 stats would be
(We'll only be looking at crucial base stats) Base health: 1995 Armor: 83.5 Magic Resistance: 53.4 Attack Damage: 116
Typical Fiora build
+450 health, +50 attack damage, +100% base health regeneration
UNIQUE – CLEAVE: Basic Attacks deal 5 (+ 1% maximum health) bonus on-hit physical damage. Additionally, basic attacks also deal 40 (+ 2.5% maximum health) physical damage in a cone to units behind the target.
UNIQUE – CRESCENT: On your next basic attack, Cleave's damage to all targets is increased to 40 (+ 10% maximum health) and has a larger cone.
+300 health, +55 attack damage, +20% cooldown reduction
UNIQUE: Dealing physical damage to an enemy champion Cleaves them, reducing their armor by 5% for 6 seconds, stacking up to 6 times for a maximum of 30%.
UNIQUE – RAGE: Dealing physical damage grants 20 movement speed for 2 seconds. Assists on Cleaved enemy champions or kills on any unit grant 60 movement speed for 2 seconds instead. This movement speed bonus is halved for ranged champions.
+500 health, +50 armor
UNIQUE – DREADNOUGHT: Generates Momentum stacks while moving, up to 100, granting up to +60 bonus movement speed. Momentum slowly decays while Slow icon slowed and decays rapidly while immobilized or Disarm iconSilence icon pacified.
UNIQUE – CRUSHING BLOW: Basic attacks (on-hit) discharge all Momentum, dealing +1 on-hit physical damage for every 2 Momentum discharged. If 100 stacks are discharged, damage is doubled to +100 and Slow icon slows its target by 50%, decaying over 1 second.
+500 health, +25% base attack damage
Grants STERAK'S FURY upon taking 400-1800 (based on level) damage within 5 seconds (45 second cooldown).
UNIQUE – STERAK'S FURY: Grants increased size, +25% additional base attack damage, and a rapidly decaying shield based of 30% maximum health for 8 seconds.
+50 magic resistance, +55 attack damage, +10 armor pen
Upon taking magic damage that would reduce maximum health below 30%, grants LIFELINE and LIFEGRIP (90 second cooldown).
UNIQUE – LIFELINE: Grants a shield that absorbs 300 (+ 100% bonus magic resistance) magic damage for 5 seconds.
UNIQUE – LIFEGRIP: Grants +25% attack speed, +10% spell vamp and +10% life steal until out-of-combat.
UNIQUE – ENHANCED MOVEMENT: +65 flat movement speed
UNIQUE – SLOW RESIST: Reduces the effectiveness of Slow icon slows by 25%.
ALACRITY - +20 flat movement speed
So with all of these items, this is what Fiora's stats are Health: 3745 (1995 + 450 + 300 + 500 + 500) Armor: 133.5 (83.5 + 50) Magic Resist: 103.5 (53.5 + 50) Attack Damage: 276 (116 + 50 + 55 + 55) Movement Speed: 415/475 (345 + 85 + (60 DMP temporary))
Item wise
Basic Attacks deal 5 (+ 37.45) bonus on-hit physical damage. Additionally, basic attacks also deal 40 (+ 93.625) physical damage in a cone to units behind the target.
UNIQUE – CRESCENT: On your next basic attack, Cleave's damage to all targets is increased to 40 (+ 374.5) and has a larger cone.
This gives 5% armor pen for each auto, going up to 30% in 6 hits. this is easy to do with fiora's q and AA resets
Gives +60 movement speed fully stacked, a AA that deals 100 bonus damage, and slows for 50%
UNIQUE – STERAK'S FURY: Grants increased size, (24 or 69, unsure which one it uses) additional base attack damage, and a rapidly decaying shield based of (1123) maximum health for 8 seconds.
UNIQUE – LIFELINE: Grants a shield that absorbs 300 (+ 103.5) magic damage for 5 seconds.
UNIQUE – LIFEGRIP: Grants +25% attack speed, +10% spell vamp and +10% life steal until out-of-combat.
+85 movement speed, and 25% resistance to slows.
Abilities Q level 5 damage: 424.625 105 (+115% (184) bonus AD) + Titanic (passive crescent: 133.625) Cooldown: 1.6 seconds 8 seconds + (20% CDR) + (60% Reduction if enemy hit)
W level 5 damage: 250 (+ 50% AS/Movement speed slow, and a stun if it catches CC) Cooldown: 12 seconds (can block ANY ability for .075 seconds every 12 seconds) 15 seconds (20% CDR)
E level 5 damage: 50% AS boost (first slows for 60%, next crits for 554) Cooldown: 5.6 seconds 7 seconds (20% CDR)
Ultimate level 3/Passive damage: 7.5% TRUE damage per vital (max 30% versus ulted target) 3% (+ 4.5%) of target's maximum health bonus true damage, heal Fiora for 110 and grant her 50% bonus movement speed that decays over 1.75 seconds. Heal: 305 per second, Max 1528 with all 4 vitals hit 140 + (165 Bonus AD)
So now you can see the math for why shes so powerful, after doing a ton of math. Ik its poorly formatted but im tired atm so i'll finish it later :)