Before we begin we need to fully understand 2 things.

Your E ability has a 200% AD ratio, that is literally 2x damage of a normal auto attack every time you press it.

Your E ability at max rank and full build has less than a 2 second cooldown.

If we understand both of these things than we can start to see the vision for this build. An ability spamming, Mike Tyson uppercutting, long range hook sniping steam golem bullying enemy top laners.

Passive - Grants a shield based off mana (this may be a very poewrful factor if you build the tank build)

Q - The iconic blitzcrank hook, useful for starting fights and securing picks at any stage in the game.

W - Blitzcrank's W unfortuately is a forgotten ability by many league players. However it is an important factor of this build as it gives movespeed and attackspeed to win trades and chase down enemies.

E - The key to this build, an ability 200% AD scaling and less then a 2 second cooldown late game. 1v1s become as easy as pressing E every time this ability is up and watching the enemy tilt.

R - What would a champion be wihtout there ultimate (ask jayce, nidalee, or elise), Blitz ult packs massive damage even without building AP and silences an entire enemy team. This damage is very strong to supris opponents and win fights in lane, and silencing an entire enemy team for 1/2 second can be the key disruption to winning a teamfight.

Whether we want to build Damage or Tank, we are going to need to maximize ability haste.

Mythics that give us Ability Haste are strong, Lucidity boots are a must.

Any item that gives Ability Haste are viable, the ones that give the most give your the most wins.

It's not complicated, I've left the items I reccomend handily available in this very guide.

So we have our ability haste, our E maxed out first, and we are ready to spam our abilities.

You may be left with an important question, how do I actually play now.

Early game - we are going to look for trading patterns with minions and good opporotuniites to land hooks. Your E cooldown is very high until you have 3+ points put into it. Don't force anything, if you opponent gets ahead the game may be lost.

Mid game - at this point we should have our E at a low cooldown and our ult ready. Most people are expecting us to build the 1 shot AP style of off meta crank. Instead we are fully ready to take any fight that comes to us with our consistent cc abilty and attack speed steroid on W. If they get below 40% hp hit you ult and get a suprise kill.

Late game - We can win just about any 1v1 that comes to us so we are gonna be focused on splitpushing. We've got the ability to punish other top laners that think they can beat us. And our E spam allows us to push waves with relative ease.

Now go play some Bouncy Blitzcrank.