Kayle

Strengths

Using Divine Judgment on a high-DPS ally can turn the tides of battle by giving your ally free reign to attack.
Kayle's attacks become incredibly powerful once she gains attack range from Divine Ascent. Play safe until then.
Kayle benefits greatly from Attack Damage and Ability Power, making hybrid items like Nashor's Tooth and Hextech Gunblade very effective on her.

Passive · Divine Ascent — Kayle's attacks are empowered by the heavens as she levels up and spends skill points. Her wings are lit aflame as she progressively gains Attack Speed, Move Speed, Attack Range, and waves of fire on her attacks.
Q · Radiant Blast — Kayle conjures a portal, summoning a celestial sword that pierces through enemies, slowing, damaging, and reducing the resistances of all hit.
W · Celestial Blessing — Blessed by the divine, Kayle heals and grants Move Speed to herself and the nearest ally.
E · Starfire Spellblade — Passive: Kayle's celestial sword, Virtue, deals bonus magic damage to enemies she attacks. Active: Kayle's next attack smites her target with celestial fire, dealing bonus damage proportionate to their missing health.
Ultimate · Divine Judgment — Kayle makes an ally invulnerable and calls upon former Aspects of Justice to purify the area around her target with a holy rain of swords.

A suggested 5-lane lineup built around Kayle, based on hero partnerships and role synergy — not win rate.