Because we don't use the tank runes we need to build tanky items. And we need to reach the enemy so dead man's armor and boots of swiftness are extremely important to gain speed. If enemy has more ad than ap build armor items and probably the only magic resist item you need is Spirit Visage. (if enemy has only ad than it is optional but I usually don't pick any magic resist)

If enemy support pick thresh, nautilus, or like this engage champs (blitzcrank is an exception) let them hook your ADC! Because when the enemy support out of the way you can easily get enemy ADC because usually enemy ADC instantly goes to your ADC to kill it so they ignore you until its too late. Surely your ad lost %50 health but this time around you hit 3 aa and with q spell, you stun the enemy ADC. In stun you can hit 2 more aa and generally enemy ADC uses his flash if he has. If not then you can easily hit the last aa and you can use w spell on him. Don't forget to use exhaust when you attack enemy ADC. Congrats you kill the enemy ADC. Now both you and your ADC can kill the only enemy support.
Note: If enemy ADC runs away from you don't hesitate to use your q and slow him.
Note: Don't wait to use your e skill until you have 10 health.

Pros:

* Very tanky
* High CC.
* Can protect anyone in team fights
* Can dive enemy turret with someone(because of w spell you can rescue your mate)
* W can use over small walls! (rescue from other side or throw to the other side)
* Sustain(e spell will regenerate your hp when out of fights if its passive works)

Cons:

* Lack of mobility
* Can't do much in the late game
* Other players generally don't know your w spell mechanic. so they throw themself into enemies (and ask you why you throw them).
* Because of the runes you can't protect very well in team fights.