So this is my first build and i really wish that someone tries it. You are just a grabbing steam golem which is just awesome. Because of mana barrier you cant even die. You must remember not to go alone because you dont do that much dmg that would kill someone, Blitz always needs team mates help to get someone down.

CORE ITEMS
You MUST buy
Shurelya's Battlesong Because of speed active so NO-ONE can't escape from you and ur team, just pull them back if they're escaping with Ghost or something fast.
Boots of Swiftness They just make you fast.
Frozen Heart Because of mana and cooldown reduction it is just must item to you.
Rylai's Crystal Scepter It will give you much health and AP and slow so your enemies just cant get away from you.

I've decided to go on 9/0/21 masteries because of you get mana regen and cooldown reduction from Utility mastey tree. You can also go 9/21/0 mastery tree if you want even more tanky Blitz.
Remember that you must take Archaic Knowledge from offensive masteries.

So first you just take Rocket Grab for firstblood you just grab someone out of brush or into turret and thats it. Then you take Power Fist to hit them into air. Then Overdrive just for extra speed.

Exhaust is must! You can get easily kills at start when you just Rocket Grab someone to tower and Power Fist them into air and put exhaust an them so turret will slain it and you get the kill. So easy!
To second spell you can take Ignite or Flash. You really dont need Ghost believe me. you are incredibly fast with Boots of Swiftness and your Overdrive. Shurelya's Battlesong is your Ghost .