League of Legends (LoL) Question: best build of blistank sp can someone help me

Blitzcrank is a pretty versatile champion. Start with Relic Shield and pots and the rest is based around the game. Mana items like Frozen Heart are very efficient on him, but don't limit yourself to them. Redemption is really strong in general if you can use it, it's a fine rush. Mikael's Blessing is great if you find your carries get hard CCd all the time. Locket of the Iron Solari is good.

Personally, I'm against Mobility Boots and in favor of Boots of Swiftness. They reduce the slow of Overdrive, so I'd say they're pretty close in roaming, and swifties simply outclass mobility hard during skirmishes. Whatever the boot upgrade, get it early.

Iceborn Gauntlet is a funny item, but I find Frozen Heart better in most of the cases were you need armor. The AS reduction really adds up.

Dead Man's Plate is a really selfish item, so don't get it. Get Randuin's Omen if you really need armor and HP. The MS is nice on paper, but if you really have to chase that hard, either your team can't catch up or you're going to get caught. That said, if you really can't catch up to the enemy, get Turbo Chemtank instead. Then your team can actually join in.

In general, look for items with utility for your team, cooldown reduction and preferably some tankiness. face of the mountain is pretty great for that reason, and so are most of the other items mentioned above.

AP BLITZCRANK!!!

Here's a link to the most popular Blitzcrank guide: http://www.mobafire.com/league-of-legends/build/blitzcrank-the-robocop-of-lol-season-7-349502

1) face of the mountain
2) Ruby Sightstone
3) Iceborn Gauntlet
4) Dead Man's Plate
5) Knight's Vow
6) Mobility Boots