Not a basic hero. A good build for a good player, if you can use 3th skill well and you can understand when to atack when to rambo. Build gives you change for immortality and being everywhere that helps with kills that run out or gives you change to be critical places when your team needs your silence and ultimate.
(a little think if you farm a diffusal as I said, you should use it's active for slow)
General Idea (What to do)
In teamfights, you must help your teammades by using the ultimate and 1st skill well. If you get used to use 1st skill, it is not that hard. Also, farming is very important for this hero.
Because of heroes 3rd skill, you can easily tower dive and get many kill but be sure that you get used to hero first. You must farm creeps. Most probably, you will farm mid so you should make some ganks. While playing puck, you should watch the game very well and use your abilities to puck in or puck out. Never chase a stunner.
-Null talisman: You need 2 null talismans because hero needs some damage to farm creeps and get kills (even for harass).
-Power Treads: You need attack speed. Also dont forget to change the Power treads to agility before using bottle.
-Bottle: Because you are an int, you easily can lose hp and get harassed. For that, you need an endless potion. Also, you need to bottle good runes and use them when you need.
-Force Staff: Its an item very functional. You can run away or chase some1 with it. You can also use it to save your friends. (If bloodseeker in game, it is necessary)
-Aganim: You will need to power your ultimate by mid and laid game. It also gives you stats and hp.
-Mystic Staff: When you get many kills and you finished these items, you will need some damage and mana. Mystic staff can be upgraded to shiva or scythe of Vyse.