Ashe the huntress
I think one advantage of Ashe, that it attacks of far which helps escape
This is just a test build.

-9x on desolation because armor penetration helps you kill the opponent.

-6x on mana regen because MP is important.

-15x on cooldowns because helps a lot in combat.

-3x on speed because speed helps to escape.

-2x on health because help if someone comes by surprise.

when you don't have a slot to make one item sale Doran's Blade.

-Doran's Blade:
10 Attack Damage, 100 Health, 3 Life Steal.

-Berserker's Greaves:
25 Attack Speed. UNIQUE Passive: Enhanced Movement 2.

-Zeal:
20 Attack Speed, 10 Critical Strike Chance, 8 Movement Speed.

-B.F. Sword:
45 Attack Damage.

-Infinity Edge:
80 Attack Damage, 25 Critical Strike Chance. UNIQUE Passive: Critical Hits now deal 250% instead of 200%.

-Emblem of Valour:
17 Life Steal. UNIQUE Aura: Nearby allied Champions gain 10 Health Regen per 5 sec.

-Phantom Dancer:
55 Attack Speed, 30 Critical Strike Chance, 15 Movement Speed.

-Last Whisper:
40 Attack Damage. UNIQUE Passive: Attacks penetrate 40% of the defender's armor.

-Stark's Fervor:
20 Attack Speed. UNIQUE Aura: Gives nearby allies Champions 20% lifesteal, 20% Attack Speed, and 30 Health per 5 seconds regenerated. Reduces the Armor of nearby enemy champions by 20.

-Banshee's Veil:
375 Health, 375 Mana, 50 Magic Resist. UNIQUE Passive: Blocks one negative spell every 45 seconds.

Flash:

Teleports your champion to target nearby location.

OR

Heal:

Restores 140 + 20x Level Health to your Champion and 50% of that to nearby allies.

AND

Ghost:

Your champion ignores unit collision and moves 27% faster for 10 seconds.