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.
Start off with the Regrowth Pendant.
Health Potion is a waste of money if you play smart in the lane.
Regrowth Pendant will allow you to stay in the lane long enough to make money for Boots of Swiftness.
Force of Nature is a great start, because of the movement speed.
You can now farm the lanes, and you are fast enough to jungle and head right back to the lane for extra gold.
Mord is great for gaining gold, so Warmog's Armor is really not that pricey for him.
Warmog's Armor is what makes Mord a tank, so it is a must have for him.
You have your magic resist with Force of Nature, so Thornmail is a great way to go for playing against attack damage.
After you get frozen mallet it is pretty much game over.
In team fights make sure you get a Children of the Grave and Ignite on a champion. (Usually put it on the one taking the most damage.)
Having your pet can totally turn a team fight around.
Even if some of your teammates die your pet and someone who stays alive with you can push the middle in no time.
This is how many of my games are won.
I have been in many games that looked hopeless, but once you have a team fight and stay alive with your pet it can be a total turn around when you take out their middle turret and inhibitor.
Mord really is a game changer.
Even if your team is losing in the first half of the game, once Mord is suited up he can lead the team to victory.