Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This blitz is for partnering up in the lane. The objective early on is to lure them close enough to turret range so u can rocket grab them and power fist them up, giving your partner a kill or the turret will kill them.
Mid/Late game you have enough health and mana to sufficiently tank. You want to get items that give both mana and health gains, after banshees veil u can go whatever path you want. If u feel that u need to do more damage then go straight ap. Items like frozen mallet arent really needed but the slow is just an extra thing to make sure the kill.
Basically the object is to feed ur teammates, while you have to be able to have enough health to survive early game.
I suggest building half of RoA as ur first item then get boots cos blitz is fairly slow, then finish RoA. Innervating locket is a very good item for this build and it helps alot.
Ghost isnt really need for blitz because he has overdrive, just be careful when to use it because when it runs out ur slower then normal for a little bit. Exhaust and ignite help your teammates get the kills. You are just there to take hits and hold them steady to give your team enough time to kill them.
The rune page can be changed to your liking but i find that health and dodge are usually just the best things you can have to be able to take enough damage and making use of nimbleness.