This is not supposed to be a competitive build, just the best and funniest to play I tried so far so feel free to adapt it to your playing styles, especially about runes and masteries. I hope you will enjoy it ;D

These may not be the more suitable runes for this role but they helped me more than one time. If I had to make some changes I would change mana reg ones with movement speed or life steal ones, maybe I'll try out someday.

You would like to take 3 Offense points away form Vampirism to put them into Initiator; it would be a nice alternative. But please, do not remove any other Offense points if you still want to have your role in early teamfights and a fair sustain in jungle.

Start with Cloth Armor and 5 Health pots for a easy early jungle (call a pull for Blue buff!). After Red Buff go for some ganks if available, if not recall and buy your shoes, then back to jungle/ganks when possible; also cover yout mates in lane if they have to recall (but do not push their lanes, just last hit!).
If you made some successfull ganks you should have enough money to buy your Giant Belt, if not you can opt for an Heart of Gold (which you can sell in late game or upgrade in Randuin in order to get some armor and a nice debuff).
Keep your gold incoming and soon you should be able to buy a Sheen, a Phage and to upgrade your shoes into Ninja Tabi/Mercury's, according to enemies damage output.
Now look at your game: if your team needs a more reliable tank go for a Sunfire Cape (for enpowered area-damage, hp and armor), if they need more damage go for Trinity (of which you have 2/3 items).
Time to make that Trinity works correctly: as soon as possible grab that Atma and watch your enemies' life going down.
A major boost will occurr as you build your Warmog, but probably you will do it in some time and the enemy team should have built a few defensive stuffs.
The last item is very occasional: if you are having problems with those AP nukes grab a Force of Nature (it boosts your speed as well ;D); if they have an overfed AD carry you would like to upgrade that Hearth of Gold into a Randuin but a Thornmail or a Frozen Heart should work well too; if your team lacks of damage you may want to build a Black Cleaver or even an Infinity Edge; if enemies have some Armor or if your mages need a help in their damage output you could think about that Abyssal Scepter.

Jungling = Smite, no discussions. As second skill I prefer Flash because I feel comfortable with a second escape tool (the other is Hecarim's ulti) but if you prefer you would like to take Ghost as it synergies far better with Devastating Charge.

In a teamfight you can have 2 roles:
1) if a tank is in your team let him initiate the fight and take the aggro, then you quicly join the action but use only Rampage: if the enemy carries focus yours you can use your Charge/Ulti to break the focus and if they aim at you use your healing skill.
2) If you have to initiate the fight use your ulti but be sure to have your carries ready to bring destruction while the fear is acting or you will have just wasted it; DO NOT use your healing skill as you reach the enemy team but wait to be focused (with the right items enemis will do it soon); if they focus your carries use your charge (see above) but you can use it to escape as well.
Remember that Spirit of the Dread grants you max survivability only in teamfights so try to time it with the area-spells of your team: the much damage the enemies take, the much health you recover.
TIP: if you want to blow up a single enemy champion (dangerous carry in teamfight or ganking lanes) try to (just) activate Devastating Charge -> Ghost/Flash -> Ulti -> Hit with the Charge. Bricks will be s**t.