Hello! I'm Sh00tme, and this is my Kayle build.
This is my first guide ever, so please tell me what to do better!

I just love to play with her and wanted to share my build with you.
She has high DPS, powerfull nuke/slow, that makes target to take more damage from you, heal/speed puff, AA modification that gives range, extra magic damage and splash damage.
And top of all that, ult that makes you or one of your team mates invulnerable for couple of seconds.

Go 9/0/21, to make your magic-side stronger. Also get some CDR for Righteous Fury.

Not really the best choises to Kayle, but still good for me.

Why these runes?

Penetration is never bad, right? I personally like more mpen marks than armorpen's on Kayle.
That's why i use Greater Mark of Magic Penetration

Kayle deal most of her damage with AA's, so i picked Greater Seal of Attack Speed and Greater Quintessence of Attack Speed

You need CDR to keep you Righteous Fury on. You get 25% from Nashor's Tooth and 10% from masteries, so you still need 5% form runes. 8 Greater Glyph of Cooldown Reduction and you have it.
Wait, still 1 Glyph? I use Greater Glyph of Ability Power in that last place.

Kayle uses her mana pretty quickly, so start with Meki Pendant and 2 Heal Potion.
It can later be upgraded to Nashor's Tooth, what is really awesome item to Kayle. You get AP, AS, manaregen and CDR for that and I think it's one of best items you can get to Kayle.

Berserker's Greaves are only boots that fit to this Kayle, so buy them. And buy them ASAP, right aftes Fiendish Codex.

Gaining heal if attacking some1? Ok, cool, let's pick Vampiric Scepter and Hextech Revolver. They can be upgraded to Hextech Gunblade after you finish you Guinsoo's Rageblade. Buy Pickaxe before Blasting Wand if you can't buy all at once.

Earlier, I really thought Trinity Force is just overpriced item that no champion can fully use. Then i tried it on Kayle, it was awesome! It really has everything you need. I prefer buying Zeal first, then Phage.

Only 5 items? Yeah, you are right. When comes time for last item, you should check your team and enemy team. Do you need more defensive stats or just full offensive?

If defensive, pick one of these:

Allways good choise
Enemmy auto-attackers are your problem? Here, **** this
If you think your Intervention isn't enough, pick this. Reborning is fun :)
Block's next enemy spell, good against casters

If going pure offensive, here are some items:

Your team need more physical power?

More and bigger crits.
More speed, more crits, more AS. Ok, cool.
Enemy building lot of armor? As I say, penetration is allways good for you.
More AD, more lifesteal

Your team need more magic damage?

More AP = More damage
Enemy building lot of MR? Penetration <3

Intervention> Righteous Fury> Reckoning> Divine Blessing

This is what you should do.

If having problem with heal, add couple of levels to Divine Blessing before starting to lever your Q.

Allways take level to R when possible, nothing special here.

I use Ignite and Flash allmost every game.

Other possibilities are:
If feel like not needing ignite, this is great choise
Don't like flash? Pick this and come super-speeded!

So here we go, please test this and tell me what you think.
My english may not be perfect, cause I don't speak it IRL.

Comments are wellcome, all kind of